How to Async Tests in Elixir →

Proper, robust asynchronous tests solve slow and flaky test suites through horizontal scaling and process isolation.

Andrea Leopardi digs into why async testing gets hard in Elixir as apps grow — singletons and shared state are the usual culprits. The practical advice here is solid: think like a library author, avoid hardcoded singletons, and leverage tools like ProcessTree and nimble_ownership for resource isolation. A great reference if your test suite is getting slow or flaky.