Add upload/download tests for size boundaries and concurrency

- Add size boundary tests: 1B, 1KB, 10KB, 100KB, 1MB, 5MB, 10MB, 50MB
- Add large file tests (100MB-1GB) marked with @pytest.mark.large
- Add chunk boundary tests at 64KB boundaries
- Add concurrent upload/download tests (2, 5, 10 parallel)
- Add data integrity tests (binary, text, unicode, compressed)
- Add generate_content() and sized_content fixture for test helpers
- Add @pytest.mark.large and @pytest.mark.concurrent markers
- Fix Content-Disposition header encoding for non-ASCII filenames (RFC 5987)

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
+- Added comprehensive upload/download tests for size boundaries (1B to 1GB)
+- Added concurrent upload/download tests (2, 5, 10 parallel operations)
+- Added data integrity tests (binary, text, unicode, compressed content)
+- Added chunk boundary tests for edge cases
+- Added `@pytest.mark.large` and `@pytest.mark.concurrent` test markers
+- Added `generate_content()` and `generate_content_with_hash()` test helpers
+- Added `sized_content` fixture for generating test content of specific sizes
 - Added production deployment job triggered by semantic version tags (v1.0.0) with manual approval gate (#63)
 - Added production Helm values file with persistence enabled (20Gi PostgreSQL, 100Gi MinIO) (#63)
 - Added integration tests for production deployment (#63)
@@ -31,6 +38,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improved pod naming: Orchard pods now named `orchard-{env}-server-*` for clarity (#51)
 
 ### Fixed
+- Fixed Content-Disposition header encoding for non-ASCII filenames using RFC 5987
 - Fixed deploy jobs running even when tests or security scans fail (changed rules from `when: always` to `when: on_success`) (#63)
 - Fixed python_tests job not using internal PyPI proxy (#63)
 - Fixed `cleanup_feature` job failing when branch is deleted (`GIT_STRATEGY: none`) (#51)

backend/app/routes.py

@@ -140,6 +140,31 @@ def sanitize_filename(filename: str) -> str:
     return re.sub(r'[\r\n"]', "", filename)
 
 
+def build_content_disposition(filename: str) -> str:
+    """Build a Content-Disposition header value with proper encoding.
+
+    For ASCII filenames, uses simple: attachment; filename="name"
+    For non-ASCII filenames, uses RFC 5987 encoding with UTF-8.
+    """
+    from urllib.parse import quote
+
+    sanitized = sanitize_filename(filename)
+
+    # Check if filename is pure ASCII
+    try:
+        sanitized.encode('ascii')
+        # Pure ASCII - simple format
+        return f'attachment; filename="{sanitized}"'
+    except UnicodeEncodeError:
+        # Non-ASCII - use RFC 5987 encoding
+        # Provide both filename (ASCII fallback) and filename* (UTF-8 encoded)
+        ascii_fallback = sanitized.encode('ascii', errors='replace').decode('ascii')
+        # RFC 5987: filename*=charset'language'encoded_value
+        # We use UTF-8 encoding and percent-encode non-ASCII chars
+        encoded = quote(sanitized, safe='')
+        return f'attachment; filename="{ascii_fallback}"; filename*=UTF-8\'\'{encoded}'
+
+
 def get_user_id_from_request(
     request: Request,
     db: Session,
@@ -2924,7 +2949,7 @@ def download_artifact(
         )
 
         headers = {
-            "Content-Disposition": f'attachment; filename="{filename}"',
+            "Content-Disposition": build_content_disposition(filename),
             "Accept-Ranges": "bytes",
             "Content-Length": str(content_length),
             **checksum_headers,
@@ -2942,7 +2967,7 @@ def download_artifact(
 
     # Full download with optional verification
     base_headers = {
-        "Content-Disposition": f'attachment; filename="{filename}"',
+        "Content-Disposition": build_content_disposition(filename),
         "Accept-Ranges": "bytes",
         **checksum_headers,
     }
@@ -3124,7 +3149,7 @@ def head_artifact(
 
     # Build headers with checksum information
     headers = {
-        "Content-Disposition": f'attachment; filename="{filename}"',
+        "Content-Disposition": build_content_disposition(filename),
         "Accept-Ranges": "bytes",
         "Content-Length": str(artifact.size),
         "X-Artifact-Id": artifact.id,

backend/pytest.ini

@@ -12,6 +12,8 @@ markers =
     unit: Unit tests (no external dependencies)
     integration: Integration tests (require database/storage)
     slow: Slow tests (skip with -m "not slow")
+    large: Large file tests (100MB+, skip with -m "not large")
+    concurrent: Concurrent operation tests
 
 # Coverage configuration
 [coverage:run]

backend/tests/conftest.py

@@ -32,6 +32,8 @@ from tests.factories import (
     compute_md5,
     compute_sha1,
     upload_test_file,
+    generate_content,
+    generate_content_with_hash,
     TEST_CONTENT_HELLO,
     TEST_HASH_HELLO,
     TEST_MD5_HELLO,
@@ -271,3 +273,41 @@ def test_content():
     content = f"test-content-{uuid.uuid4().hex}".encode()
     sha256 = compute_sha256(content)
     return (content, sha256)
+
+
+@pytest.fixture
+def sized_content():
+    """
+    Factory fixture for generating content of specific sizes.
+
+    Usage:
+        def test_example(sized_content):
+            content, hash = sized_content(1024)  # 1KB
+            content, hash = sized_content(1024 * 1024)  # 1MB
+    """
+    def _generate(size: int, seed: int = None):
+        return generate_content_with_hash(size, seed)
+    return _generate
+
+
+# =============================================================================
+# Size Constants for Tests
+# =============================================================================
+
+# Common file sizes for boundary testing
+SIZE_1B = 1
+SIZE_1KB = 1024
+SIZE_10KB = 10 * 1024
+SIZE_100KB = 100 * 1024
+SIZE_1MB = 1024 * 1024
+SIZE_5MB = 5 * 1024 * 1024
+SIZE_10MB = 10 * 1024 * 1024
+SIZE_50MB = 50 * 1024 * 1024
+SIZE_100MB = 100 * 1024 * 1024
+SIZE_250MB = 250 * 1024 * 1024
+SIZE_500MB = 500 * 1024 * 1024
+SIZE_1GB = 1024 * 1024 * 1024
+
+# Chunk size boundaries (based on typical S3 multipart chunk sizes)
+CHUNK_SIZE = 64 * 1024  # 64KB typical chunk
+MULTIPART_THRESHOLD = 100 * 1024 * 1024  # 100MB multipart threshold

backend/tests/factories.py

@@ -97,6 +97,7 @@ def upload_test_file(
     content: bytes,
     filename: str = "test.bin",
     tag: Optional[str] = None,
+    version: Optional[str] = None,
 ) -> dict:
     """
     Helper function to upload a test file via the API.
@@ -108,6 +109,7 @@ def upload_test_file(
         content: File content as bytes
         filename: Original filename
         tag: Optional tag to assign
+        version: Optional version to assign
 
     Returns:
         The upload response as a dict
@@ -116,6 +118,8 @@ def upload_test_file(
     data = {}
     if tag:
         data["tag"] = tag
+    if version:
+        data["version"] = version
 
     response = client.post(
         f"/api/v1/project/{project}/{package}/upload",
@@ -126,6 +130,41 @@ def upload_test_file(
     return response.json()
 
 
+def generate_content(size: int, seed: Optional[int] = None) -> bytes:
+    """
+    Generate deterministic or random content of a specified size.
+
+    Args:
+        size: Size of content in bytes
+        seed: Optional seed for reproducible content (None for random)
+
+    Returns:
+        Bytes of the specified size
+    """
+    if size == 0:
+        return b""
+    if seed is not None:
+        import random
+        rng = random.Random(seed)
+        return bytes(rng.randint(0, 255) for _ in range(size))
+    return os.urandom(size)
+
+
+def generate_content_with_hash(size: int, seed: Optional[int] = None) -> tuple[bytes, str]:
+    """
+    Generate content of specified size and compute its SHA256 hash.
+
+    Args:
+        size: Size of content in bytes
+        seed: Optional seed for reproducible content
+
+    Returns:
+        Tuple of (content_bytes, sha256_hash)
+    """
+    content = generate_content(size, seed)
+    return content, compute_sha256(content)
+
+
 # =============================================================================
 # Project/Package Factories
 # =============================================================================

backend/tests/integration/test_concurrent_operations.py

@@ -0,0 +1,737 @@
+"""
+Integration tests for concurrent upload and download operations.
+
+Tests cover:
+- Concurrent uploads of different files
+- Concurrent uploads of same file (deduplication race)
+- Concurrent downloads of same artifact
+- Concurrent downloads of different artifacts
+- Mixed concurrent uploads and downloads
+- Data corruption prevention under concurrency
+"""
+
+import pytest
+import io
+import os
+from concurrent.futures import ThreadPoolExecutor, as_completed
+from tests.factories import (
+    compute_sha256,
+    upload_test_file,
+    generate_content_with_hash,
+)
+
+
+def get_api_key(integration_client):
+    """Create an API key for concurrent test workers."""
+    import uuid
+    response = integration_client.post(
+        "/api/v1/auth/keys",
+        json={"name": f"concurrent-test-{uuid.uuid4().hex[:8]}"},
+    )
+    if response.status_code == 200:
+        return response.json()["key"]
+    return None
+
+
+class TestConcurrentUploads:
+    """Tests for concurrent upload operations."""
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_2_concurrent_uploads_different_files(self, integration_client, test_package):
+        """Test 2 concurrent uploads of different files."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        files_data = [
+            generate_content_with_hash(1024, seed=i) for i in range(2)
+        ]
+
+        results = []
+        errors = []
+
+        def upload_worker(idx, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"file-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"concurrent-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        result = response.json()
+                        results.append((idx, result, expected_hash))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}: {response.text}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=2) as executor:
+            futures = [
+                executor.submit(upload_worker, i, content, hash)
+                for i, (content, hash) in enumerate(files_data)
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == 2
+
+        # Verify each upload returned correct artifact_id
+        for idx, result, expected_hash in results:
+            assert result["artifact_id"] == expected_hash
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_5_concurrent_uploads_different_files(self, integration_client, test_package):
+        """Test 5 concurrent uploads of different files."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        num_files = 5
+        files_data = [
+            generate_content_with_hash(2048, seed=100 + i) for i in range(num_files)
+        ]
+
+        results = []
+        errors = []
+
+        def upload_worker(idx, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"file-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"concurrent5-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        result = response.json()
+                        results.append((idx, result, expected_hash))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_files) as executor:
+            futures = [
+                executor.submit(upload_worker, i, content, hash)
+                for i, (content, hash) in enumerate(files_data)
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_files
+
+        # Verify all uploads have unique artifact_ids
+        artifact_ids = set(r[1]["artifact_id"] for r in results)
+        assert len(artifact_ids) == num_files
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_10_concurrent_uploads_different_files(self, integration_client, test_package):
+        """Test 10 concurrent uploads of different files."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        num_files = 10
+        files_data = [
+            generate_content_with_hash(1024, seed=200 + i) for i in range(num_files)
+        ]
+
+        results = []
+        errors = []
+
+        def upload_worker(idx, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"file-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"concurrent10-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        result = response.json()
+                        results.append((idx, result, expected_hash))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_files) as executor:
+            futures = [
+                executor.submit(upload_worker, i, content, hash)
+                for i, (content, hash) in enumerate(files_data)
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_files
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_concurrent_uploads_same_file_deduplication(self, integration_client, test_package):
+        """Test concurrent uploads of same file handle deduplication correctly."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        content, expected_hash = generate_content_with_hash(4096, seed=999)
+        num_concurrent = 5
+
+        results = []
+        errors = []
+
+        def upload_worker(idx):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"same-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"dedup-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        results.append(response.json())
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_concurrent) as executor:
+            futures = [executor.submit(upload_worker, i) for i in range(num_concurrent)]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_concurrent
+
+        # All should have same artifact_id
+        artifact_ids = set(r["artifact_id"] for r in results)
+        assert len(artifact_ids) == 1
+        assert expected_hash in artifact_ids
+
+        # Verify final ref_count equals number of uploads
+        response = integration_client.get(f"/api/v1/artifact/{expected_hash}")
+        assert response.status_code == 200
+        assert response.json()["ref_count"] == num_concurrent
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_concurrent_uploads_to_different_packages(self, integration_client, test_project, unique_test_id):
+        """Test concurrent uploads to different packages."""
+        project = test_project
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        num_packages = 3
+        package_names = []
+
+        # Create multiple packages
+        for i in range(num_packages):
+            pkg_name = f"pkg-{unique_test_id}-{i}"
+            response = integration_client.post(
+                f"/api/v1/project/{project}/packages",
+                json={"name": pkg_name, "description": f"Package {i}"},
+            )
+            assert response.status_code == 200
+            package_names.append(pkg_name)
+
+        files_data = [
+            generate_content_with_hash(1024, seed=300 + i) for i in range(num_packages)
+        ]
+
+        results = []
+        errors = []
+
+        def upload_worker(idx, package, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"file-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": "latest"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        result = response.json()
+                        results.append((package, result, expected_hash))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_packages) as executor:
+            futures = [
+                executor.submit(upload_worker, i, package_names[i], content, hash)
+                for i, (content, hash) in enumerate(files_data)
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_packages
+
+
+class TestConcurrentDownloads:
+    """Tests for concurrent download operations."""
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_2_concurrent_downloads_same_artifact(self, integration_client, test_package):
+        """Test 2 concurrent downloads of same artifact."""
+        project, package = test_package
+        content, expected_hash = generate_content_with_hash(2048, seed=400)
+
+        # Upload first
+        upload_test_file(integration_client, project, package, content, tag="download-test")
+
+        results = []
+        errors = []
+
+        def download_worker(idx):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/download-test",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results.append((idx, response.content))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=2) as executor:
+            futures = [executor.submit(download_worker, i) for i in range(2)]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == 2
+
+        # All downloads should match original
+        for idx, downloaded in results:
+            assert downloaded == content
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_5_concurrent_downloads_same_artifact(self, integration_client, test_package):
+        """Test 5 concurrent downloads of same artifact."""
+        project, package = test_package
+        content, expected_hash = generate_content_with_hash(4096, seed=500)
+
+        upload_test_file(integration_client, project, package, content, tag="download5-test")
+
+        num_downloads = 5
+        results = []
+        errors = []
+
+        def download_worker(idx):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/download5-test",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results.append((idx, response.content))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_downloads) as executor:
+            futures = [executor.submit(download_worker, i) for i in range(num_downloads)]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_downloads
+
+        for idx, downloaded in results:
+            assert downloaded == content
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_10_concurrent_downloads_same_artifact(self, integration_client, test_package):
+        """Test 10 concurrent downloads of same artifact."""
+        project, package = test_package
+        content, expected_hash = generate_content_with_hash(8192, seed=600)
+
+        upload_test_file(integration_client, project, package, content, tag="download10-test")
+
+        num_downloads = 10
+        results = []
+        errors = []
+
+        def download_worker(idx):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/download10-test",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results.append((idx, response.content))
+                    else:
+                        errors.append(f"Worker {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_downloads) as executor:
+            futures = [executor.submit(download_worker, i) for i in range(num_downloads)]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_downloads
+
+        for idx, downloaded in results:
+            assert downloaded == content
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_concurrent_downloads_different_artifacts(self, integration_client, test_package):
+        """Test concurrent downloads of different artifacts."""
+        project, package = test_package
+
+        # Upload multiple files
+        num_files = 5
+        uploads = []
+        for i in range(num_files):
+            content, expected_hash = generate_content_with_hash(1024, seed=700 + i)
+            upload_test_file(
+                integration_client, project, package, content,
+                tag=f"multi-download-{i}"
+            )
+            uploads.append((f"multi-download-{i}", content))
+
+        results = []
+        errors = []
+
+        def download_worker(tag, expected_content):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/{tag}",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results.append((tag, response.content, expected_content))
+                    else:
+                        errors.append(f"Tag {tag}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Tag {tag}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_files) as executor:
+            futures = [
+                executor.submit(download_worker, tag, content)
+                for tag, content in uploads
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_files
+
+        for tag, downloaded, expected in results:
+            assert downloaded == expected, f"Content mismatch for {tag}"
+
+
+class TestMixedConcurrentOperations:
+    """Tests for mixed concurrent upload and download operations."""
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_upload_while_download_in_progress(self, integration_client, test_package):
+        """Test uploading while a download is in progress."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        # Upload initial content
+        content1, hash1 = generate_content_with_hash(10240, seed=800)  # 10KB
+        upload_test_file(integration_client, project, package, content1, tag="initial")
+
+        # New content for upload during download
+        content2, hash2 = generate_content_with_hash(10240, seed=801)
+
+        results = {"downloads": [], "uploads": []}
+        errors = []
+
+        def download_worker():
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/initial",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results["downloads"].append(response.content)
+                    else:
+                        errors.append(f"Download: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Download: {str(e)}")
+
+        def upload_worker():
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": ("new.bin", io.BytesIO(content2), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": "during-download"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        results["uploads"].append(response.json())
+                    else:
+                        errors.append(f"Upload: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Upload: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=2) as executor:
+            futures = [
+                executor.submit(download_worker),
+                executor.submit(upload_worker),
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results["downloads"]) == 1
+        assert len(results["uploads"]) == 1
+
+        # Verify download got correct content
+        assert results["downloads"][0] == content1
+
+        # Verify upload succeeded
+        assert results["uploads"][0]["artifact_id"] == hash2
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_multiple_uploads_and_downloads_simultaneously(self, integration_client, test_package):
+        """Test multiple uploads and downloads running simultaneously."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        # Pre-upload some files for downloading
+        existing_files = []
+        for i in range(3):
+            content, hash = generate_content_with_hash(2048, seed=900 + i)
+            upload_test_file(integration_client, project, package, content, tag=f"existing-{i}")
+            existing_files.append((f"existing-{i}", content))
+
+        # New files for uploading
+        new_files = [
+            generate_content_with_hash(2048, seed=910 + i) for i in range(3)
+        ]
+
+        results = {"downloads": [], "uploads": []}
+        errors = []
+
+        def download_worker(tag, expected):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    response = client.get(
+                        f"/api/v1/project/{project}/{package}/+/{tag}",
+                        params={"mode": "proxy"},
+                    )
+                    if response.status_code == 200:
+                        results["downloads"].append((tag, response.content, expected))
+                    else:
+                        errors.append(f"Download {tag}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Download {tag}: {str(e)}")
+
+        def upload_worker(idx, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    files = {
+                        "file": (f"new-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    response = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"new-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if response.status_code == 200:
+                        results["uploads"].append((idx, response.json(), expected_hash))
+                    else:
+                        errors.append(f"Upload {idx}: Status {response.status_code}")
+            except Exception as e:
+                errors.append(f"Upload {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=6) as executor:
+            futures = []
+
+            # Submit downloads
+            for tag, content in existing_files:
+                futures.append(executor.submit(download_worker, tag, content))
+
+            # Submit uploads
+            for i, (content, hash) in enumerate(new_files):
+                futures.append(executor.submit(upload_worker, i, content, hash))
+
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results["downloads"]) == 3
+        assert len(results["uploads"]) == 3
+
+        # Verify downloads
+        for tag, downloaded, expected in results["downloads"]:
+            assert downloaded == expected, f"Download mismatch for {tag}"
+
+        # Verify uploads
+        for idx, result, expected_hash in results["uploads"]:
+            assert result["artifact_id"] == expected_hash
+
+    @pytest.mark.integration
+    @pytest.mark.concurrent
+    def test_no_data_corruption_under_concurrency(self, integration_client, test_package):
+        """Test that no data corruption occurs under concurrent operations."""
+        project, package = test_package
+        api_key = get_api_key(integration_client)
+        assert api_key, "Failed to create API key"
+
+        # Create content with recognizable patterns
+        num_files = 5
+        files_data = []
+        for i in range(num_files):
+            # Each file has unique repeating pattern for easy corruption detection
+            pattern = bytes([i] * 256)
+            content = pattern * 40  # 10KB each
+            hash = compute_sha256(content)
+            files_data.append((content, hash))
+
+        results = []
+        errors = []
+
+        def upload_and_verify(idx, content, expected_hash):
+            try:
+                from httpx import Client
+                base_url = os.environ.get("ORCHARD_TEST_URL", "http://localhost:8080")
+
+                with Client(base_url=base_url, timeout=60.0) as client:
+                    # Upload
+                    files = {
+                        "file": (f"pattern-{idx}.bin", io.BytesIO(content), "application/octet-stream")
+                    }
+                    upload_resp = client.post(
+                        f"/api/v1/project/{project}/{package}/upload",
+                        files=files,
+                        data={"tag": f"pattern-{idx}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
+                    )
+                    if upload_resp.status_code != 200:
+                        errors.append(f"Upload {idx}: Status {upload_resp.status_code}")
+                        return
+
+                    upload_result = upload_resp.json()
+                    if upload_result["artifact_id"] != expected_hash:
+                        errors.append(f"Upload {idx}: Hash mismatch")
+                        return
+
+                    # Immediately download and verify
+                    download_resp = client.get(
+                        f"/api/v1/project/{project}/{package}/+/pattern-{idx}",
+                        params={"mode": "proxy"},
+                    )
+                    if download_resp.status_code != 200:
+                        errors.append(f"Download {idx}: Status {download_resp.status_code}")
+                        return
+
+                    if download_resp.content != content:
+                        errors.append(f"Worker {idx}: DATA CORRUPTION DETECTED")
+                        return
+
+                    # Verify the downloaded content hash
+                    downloaded_hash = compute_sha256(download_resp.content)
+                    if downloaded_hash != expected_hash:
+                        errors.append(f"Worker {idx}: Hash verification failed")
+                        return
+
+                    results.append(idx)
+
+            except Exception as e:
+                errors.append(f"Worker {idx}: {str(e)}")
+
+        with ThreadPoolExecutor(max_workers=num_files) as executor:
+            futures = [
+                executor.submit(upload_and_verify, i, content, hash)
+                for i, (content, hash) in enumerate(files_data)
+            ]
+            for future in as_completed(futures):
+                pass
+
+        assert len(errors) == 0, f"Errors: {errors}"
+        assert len(results) == num_files

backend/tests/integration/test_size_boundary.py

@@ -0,0 +1,583 @@
+"""
+Integration tests for upload/download with various file sizes.
+
+Tests cover:
+- Small files (0B - 100KB)
+- Medium files (1MB - 50MB)
+- Large files (100MB - 1GB) - marked as slow/large
+- Exact chunk boundaries
+- Data integrity verification across all sizes
+"""
+
+import pytest
+import io
+import time
+from concurrent.futures import ThreadPoolExecutor, as_completed
+from tests.factories import (
+    compute_sha256,
+    upload_test_file,
+    generate_content,
+    generate_content_with_hash,
+)
+from tests.conftest import (
+    SIZE_1B,
+    SIZE_1KB,
+    SIZE_10KB,
+    SIZE_100KB,
+    SIZE_1MB,
+    SIZE_5MB,
+    SIZE_10MB,
+    SIZE_50MB,
+    SIZE_100MB,
+    SIZE_250MB,
+    SIZE_500MB,
+    SIZE_1GB,
+    CHUNK_SIZE,
+    MULTIPART_THRESHOLD,
+)
+
+
+class TestSmallFileSizes:
+    """Tests for small file uploads/downloads (0B - 100KB)."""
+
+    @pytest.mark.integration
+    def test_upload_download_1_byte(self, integration_client, test_package, sized_content):
+        """Test upload/download of 1 byte file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_1B, seed=1)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="1byte.bin", tag="1byte"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_1B
+
+        # Download and verify
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/1byte",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+        assert len(response.content) == SIZE_1B
+
+    @pytest.mark.integration
+    def test_upload_download_1kb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 1KB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_1KB, seed=2)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="1kb.bin", tag="1kb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_1KB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/1kb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_upload_download_10kb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 10KB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_10KB, seed=3)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="10kb.bin", tag="10kb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_10KB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/10kb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_upload_download_100kb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 100KB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_100KB, seed=4)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="100kb.bin", tag="100kb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_100KB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/100kb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+
+class TestMediumFileSizes:
+    """Tests for medium file uploads/downloads (1MB - 50MB)."""
+
+    @pytest.mark.integration
+    def test_upload_download_1mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 1MB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_1MB, seed=10)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="1mb.bin", tag="1mb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_1MB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/1mb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_1MB
+        assert compute_sha256(response.content) == expected_hash
+
+    @pytest.mark.integration
+    def test_upload_download_5mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 5MB file (multipart threshold boundary area)."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_5MB, seed=11)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="5mb.bin", tag="5mb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_5MB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/5mb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_5MB
+        assert compute_sha256(response.content) == expected_hash
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    def test_upload_download_10mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 10MB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_10MB, seed=12)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="10mb.bin", tag="10mb"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_10MB
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/10mb",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_10MB
+        assert compute_sha256(response.content) == expected_hash
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    def test_upload_download_50mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 50MB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_50MB, seed=13)
+
+        start_time = time.time()
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="50mb.bin", tag="50mb"
+        )
+        upload_time = time.time() - start_time
+
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_50MB
+
+        start_time = time.time()
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/50mb",
+            params={"mode": "proxy"},
+        )
+        download_time = time.time() - start_time
+
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_50MB
+        assert compute_sha256(response.content) == expected_hash
+
+        # Log timing for performance tracking
+        print(f"\n50MB upload: {upload_time:.2f}s, download: {download_time:.2f}s")
+
+
+class TestLargeFileSizes:
+    """Tests for large file uploads/downloads (100MB - 1GB).
+
+    These tests are marked as slow and large, skipped by default.
+    Run with: pytest -m "large" to include these tests.
+    """
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    @pytest.mark.large
+    def test_upload_download_100mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 100MB file (multipart threshold)."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_100MB, seed=100)
+
+        start_time = time.time()
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="100mb.bin", tag="100mb"
+        )
+        upload_time = time.time() - start_time
+
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_100MB
+
+        start_time = time.time()
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/100mb",
+            params={"mode": "proxy"},
+        )
+        download_time = time.time() - start_time
+
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_100MB
+        assert compute_sha256(response.content) == expected_hash
+
+        print(f"\n100MB upload: {upload_time:.2f}s, download: {download_time:.2f}s")
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    @pytest.mark.large
+    def test_upload_download_250mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 250MB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_250MB, seed=250)
+
+        start_time = time.time()
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="250mb.bin", tag="250mb"
+        )
+        upload_time = time.time() - start_time
+
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_250MB
+
+        start_time = time.time()
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/250mb",
+            params={"mode": "proxy"},
+        )
+        download_time = time.time() - start_time
+
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_250MB
+        assert compute_sha256(response.content) == expected_hash
+
+        print(f"\n250MB upload: {upload_time:.2f}s, download: {download_time:.2f}s")
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    @pytest.mark.large
+    def test_upload_download_500mb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 500MB file."""
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_500MB, seed=500)
+
+        start_time = time.time()
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="500mb.bin", tag="500mb"
+        )
+        upload_time = time.time() - start_time
+
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_500MB
+
+        start_time = time.time()
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/500mb",
+            params={"mode": "proxy"},
+        )
+        download_time = time.time() - start_time
+
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_500MB
+        assert compute_sha256(response.content) == expected_hash
+
+        print(f"\n500MB upload: {upload_time:.2f}s, download: {download_time:.2f}s")
+
+    @pytest.mark.integration
+    @pytest.mark.slow
+    @pytest.mark.large
+    def test_upload_download_1gb(self, integration_client, test_package, sized_content):
+        """Test upload/download of 1GB file.
+
+        This test may take several minutes depending on network/disk speed.
+        """
+        project, package = test_package
+        content, expected_hash = sized_content(SIZE_1GB, seed=1024)
+
+        start_time = time.time()
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="1gb.bin", tag="1gb"
+        )
+        upload_time = time.time() - start_time
+
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == SIZE_1GB
+
+        start_time = time.time()
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/1gb",
+            params={"mode": "proxy"},
+        )
+        download_time = time.time() - start_time
+
+        assert response.status_code == 200
+        assert len(response.content) == SIZE_1GB
+        assert compute_sha256(response.content) == expected_hash
+
+        print(f"\n1GB upload: {upload_time:.2f}s, download: {download_time:.2f}s")
+
+
+class TestChunkBoundaries:
+    """Tests for exact chunk size boundaries."""
+
+    @pytest.mark.integration
+    def test_upload_download_at_chunk_size(self, integration_client, test_package, sized_content):
+        """Test upload/download at exact chunk size (64KB)."""
+        project, package = test_package
+        content, expected_hash = sized_content(CHUNK_SIZE, seed=64)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="chunk.bin", tag="chunk-exact"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == CHUNK_SIZE
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/chunk-exact",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_upload_download_chunk_size_plus_1(self, integration_client, test_package, sized_content):
+        """Test upload/download at chunk size + 1 byte."""
+        project, package = test_package
+        size = CHUNK_SIZE + 1
+        content, expected_hash = sized_content(size, seed=65)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="chunk_plus.bin", tag="chunk-plus"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == size
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/chunk-plus",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_upload_download_chunk_size_minus_1(self, integration_client, test_package, sized_content):
+        """Test upload/download at chunk size - 1 byte."""
+        project, package = test_package
+        size = CHUNK_SIZE - 1
+        content, expected_hash = sized_content(size, seed=63)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="chunk_minus.bin", tag="chunk-minus"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == size
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/chunk-minus",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_upload_download_multiple_chunks(self, integration_client, test_package, sized_content):
+        """Test upload/download spanning multiple chunks."""
+        project, package = test_package
+        size = CHUNK_SIZE * 3 + 1000  # 3 full chunks + partial
+        content, expected_hash = sized_content(size, seed=300)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="multi_chunk.bin", tag="multi-chunk"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["size"] == size
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/multi-chunk",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+
+class TestDataIntegrity:
+    """Tests for data integrity with various content types."""
+
+    @pytest.mark.integration
+    def test_binary_content_integrity(self, integration_client, test_package):
+        """Test binary content (all byte values 0-255) integrity."""
+        project, package = test_package
+        # Content with all 256 possible byte values
+        content = bytes(range(256)) * 100  # 25.6KB
+        expected_hash = compute_sha256(content)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="binary.bin", tag="binary"
+        )
+        assert result["artifact_id"] == expected_hash
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/binary",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_text_content_integrity(self, integration_client, test_package):
+        """Test UTF-8 text content integrity."""
+        project, package = test_package
+        content = "Hello, World! 你好世界 🌍 مرحبا العالم".encode("utf-8")
+        expected_hash = compute_sha256(content)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="text.txt", tag="text"
+        )
+        assert result["artifact_id"] == expected_hash
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/text",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+        assert response.content.decode("utf-8") == "Hello, World! 你好世界 🌍 مرحبا العالم"
+
+    @pytest.mark.integration
+    def test_null_bytes_content_integrity(self, integration_client, test_package):
+        """Test content with null bytes."""
+        project, package = test_package
+        content = b"before\x00null\x00bytes\x00after"
+        expected_hash = compute_sha256(content)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="nulls.bin", tag="nulls"
+        )
+        assert result["artifact_id"] == expected_hash
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/nulls",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+        assert b"\x00" in response.content
+
+    @pytest.mark.integration
+    def test_unicode_filename_integrity(self, integration_client, test_package):
+        """Test file with unicode filename."""
+        project, package = test_package
+        content = b"unicode filename test"
+        expected_hash = compute_sha256(content)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="文件名.txt", tag="unicode-name"
+        )
+        assert result["artifact_id"] == expected_hash
+        assert result["original_name"] == "文件名.txt"
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/unicode-name",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+
+    @pytest.mark.integration
+    def test_compressed_content_integrity(self, integration_client, test_package):
+        """Test gzip-compressed content integrity."""
+        import gzip
+
+        project, package = test_package
+        original = b"This is some text that will be compressed " * 100
+        content = gzip.compress(original)
+        expected_hash = compute_sha256(content)
+
+        result = upload_test_file(
+            integration_client, project, package, content,
+            filename="data.gz", tag="compressed"
+        )
+        assert result["artifact_id"] == expected_hash
+
+        response = integration_client.get(
+            f"/api/v1/project/{project}/{package}/+/compressed",
+            params={"mode": "proxy"},
+        )
+        assert response.status_code == 200
+        assert response.content == content
+        # Verify we can decompress
+        assert gzip.decompress(response.content) == original
+
+    @pytest.mark.integration
+    def test_hash_verification_matches(self, integration_client, test_package, sized_content):
+        """Test that computed hash matches artifact_id for various sizes."""
+        project, package = test_package
+
+        sizes = [SIZE_1B, SIZE_1KB, SIZE_10KB, SIZE_100KB, SIZE_1MB]
+
+        for i, size in enumerate(sizes):
+            content, expected_hash = sized_content(size, seed=1000 + i)
+
+            result = upload_test_file(
+                integration_client, project, package, content,
+                filename=f"hash_test_{size}.bin", tag=f"hash-{size}"
+            )
+
+            # Verify artifact_id matches expected hash
+            assert result["artifact_id"] == expected_hash
+
+            # Download and verify hash of downloaded content
+            response = integration_client.get(
+                f"/api/v1/project/{project}/{package}/+/hash-{size}",
+                params={"mode": "proxy"},
+            )
+            downloaded_hash = compute_sha256(response.content)
+            assert downloaded_hash == expected_hash