[boyd]

Throwing cores at the problem with `pytest-xdist` is typically the lowest hanging fruit, but you still hit all the paper cuts the authors mention -- collection, DB fixtures, import time, etc.

And, further optimization is really hard when the CI plumbing starts to dominate. For example, the last Warehouse `test` job I checked has 43s of Github Actions overhead for 51s of pytest execution time (half the test action time and approaching 100% overhead).

Disclosure: Have been tinkering on a side project trying to provide 90% of these pytest optimizations automatically, but also get "time-to-first-test-failure" down to ~10 seconds (via warm runners, container snapshotting, etc.). Email in profile if anyone would like to swap notes.