diff --git a/backend/app/pypi_proxy.py b/backend/app/pypi_proxy.py
index 6832c28..5ee1f49 100644
--- a/backend/app/pypi_proxy.py
+++ b/backend/app/pypi_proxy.py
@@ -365,8 +365,8 @@ async def pypi_simple_index(
 
             timeout = httpx.Timeout(PROXY_READ_TIMEOUT, connect=PROXY_CONNECT_TIMEOUT)
 
-            with httpx.Client(timeout=timeout, follow_redirects=False) as client:
-                response = client.get(
+            async with httpx.AsyncClient(timeout=timeout, follow_redirects=False) as client:
+                response = await client.get(
                     simple_url,
                     headers=headers,
                     auth=auth,
@@ -377,7 +377,7 @@ async def pypi_simple_index(
                     redirect_url = response.headers.get('location')
                     if redirect_url:
                         # Follow the redirect once
-                        response = client.get(
+                        response = await client.get(
                             redirect_url,
                             headers=headers,
                             auth=auth,
@@ -455,8 +455,8 @@ async def pypi_package_versions(
 
             timeout = httpx.Timeout(PROXY_READ_TIMEOUT, connect=PROXY_CONNECT_TIMEOUT)
 
-            with httpx.Client(timeout=timeout, follow_redirects=False) as client:
-                response = client.get(
+            async with httpx.AsyncClient(timeout=timeout, follow_redirects=False) as client:
+                response = await client.get(
                     package_url,
                     headers=headers,
                     auth=auth,
@@ -475,7 +475,7 @@ async def pypi_package_versions(
 
                     final_url = redirect_url  # Update final URL
 
-                    response = client.get(
+                    response = await client.get(
                         redirect_url,
                         headers=headers,
                         auth=auth,
@@ -598,8 +598,8 @@ async def pypi_download_file(
         # Fetch the file
         logger.info(f"PyPI proxy: fetching {filename} from {upstream_url}")
 
-        with httpx.Client(timeout=timeout, follow_redirects=False) as client:
-            response = client.get(
+        async with httpx.AsyncClient(timeout=timeout, follow_redirects=False) as client:
+            response = await client.get(
                 upstream_url,
                 headers=headers,
                 auth=auth,
@@ -624,7 +624,7 @@ async def pypi_download_file(
                     redirect_headers.update(headers)
                     redirect_auth = auth
 
-                response = client.get(
+                response = await client.get(
                     redirect_url,
                     headers=redirect_headers,
                     auth=redirect_auth,
@@ -642,11 +642,12 @@ async def pypi_download_file(
 
             # Stream to temp file to avoid loading large packages into memory
             # This keeps memory usage constant regardless of package size
+            # Using async iteration to avoid blocking the event loop
             tmp_path = None
             try:
                 with tempfile.NamedTemporaryFile(delete=False, suffix=f"_{filename}") as tmp_file:
                     tmp_path = tmp_file.name
-                    for chunk in response.iter_bytes(chunk_size=65536):  # 64KB chunks
+                    async for chunk in response.aiter_bytes(chunk_size=65536):  # 64KB chunks
                         tmp_file.write(chunk)
 
                 # Store in S3 from temp file (computes hash and deduplicates automatically)