diff --git a/backend/app/dependencies.py b/backend/app/dependencies.py
index 30463b9..c3c4b06 100644
--- a/backend/app/dependencies.py
+++ b/backend/app/dependencies.py
@@ -806,6 +806,10 @@ def resolve_dependencies(
             if dep_artifact_id == artifact_id:
                 continue
 
+            # Skip if this artifact is already being visited (would cause cycle)
+            if dep_artifact_id in visiting:
+                continue
+
             _resolve_recursive(
                 dep_artifact_id,
                 dep.dependency_project,
@@ -1142,14 +1146,19 @@ async def resolve_dependencies_with_fetch(
         ).all()
 
         for dep in deps:
-            # Skip self-dependencies
+            # Skip self-dependencies (common with PyPI extras like pytest[testing] -> pytest)
             dep_proj_normalized = dep.dependency_project.lower()
             dep_pkg_normalized = _normalize_pypi_package_name(dep.dependency_package)
             curr_proj_normalized = proj_name.lower()
             curr_pkg_normalized = _normalize_pypi_package_name(pkg_name)
             if dep_proj_normalized == curr_proj_normalized and dep_pkg_normalized == curr_pkg_normalized:
+                logger.debug(
+                    f"Skipping self-dependency: {pkg_key} -> {dep.dependency_project}/{dep.dependency_package}"
+                )
                 continue
 
+            # Also check if this dependency would resolve to the current artifact
+            # (handles cases where package names differ but resolve to same artifact)
             resolved_dep = _resolve_dependency_to_artifact(
                 db,
                 dep.dependency_project,
@@ -1185,7 +1194,20 @@ async def resolve_dependencies_with_fetch(
 
             dep_artifact_id, dep_version, dep_size = resolved_dep
 
+            # Skip if resolved to same artifact (self-dependency at artifact level)
             if dep_artifact_id == artifact_id:
+                logger.debug(
+                    f"Skipping self-dependency (same artifact): {pkg_key} -> "
+                    f"{dep.dependency_project}/{dep.dependency_package} (artifact {dep_artifact_id[:12]})"
+                )
+                continue
+
+            # Skip if this artifact is already being visited (would cause cycle)
+            if dep_artifact_id in visiting:
+                logger.debug(
+                    f"Skipping dependency already in resolution stack: {pkg_key} -> "
+                    f"{dep.dependency_project}/{dep.dependency_package} (artifact {dep_artifact_id[:12]})"
+                )
                 continue
 
             await _resolve_recursive_async(