PyPI's Warehouse: 81% Faster Test Suite with Simple Optimizations
2025-05-12
Trail of Bits dramatically improved the performance of PyPI's Warehouse test suite, reducing execution time from 163 seconds to 30 seconds while increasing the test count from 3,900 to over 4,700. This 81% improvement was achieved through several key optimizations: parallelizing test execution with pytest-xdist, leveraging Python 3.12's sys.monitoring for efficient coverage instrumentation, optimizing test discovery, and eliminating unnecessary imports. These techniques are readily applicable to many Python projects struggling with slow test suites, offering significant performance gains at minimal cost.
Development
Testing Optimization