I Replaced pytest-xdist With 60 Lines of subprocess.Popen. Here's Why.

A flaky Python test suite was traced to shared state leaking across pytest-xdist workers.

The team replaced xdist with a launcher that starts one fresh Python process per test file using subprocess.Popen and bounded parallelism.

This kept runtime manageable while eliminating cross-file leakage and stabilizing CI.

The article also stresses killing entire subprocess trees on timeout to avoid orphaned grandchildren.