tests taking minutes is usually a symptom of integration creep, not just slow code. once you have a few slow e2e flows, they dominate wall clock unless you shard + run in parallel.

what helped us: split unit vs contract vs e2e, keep e2e <10%, and treat long tests like a queue (retry, quarantine flaky). ai can write test scaffolding fast but it also encourages over-testing the wrong layer.