Four engineers, one invoicing product, no QA team. This is the risk-based testing strategy we settled on: integration tests over mocks, contract tests at service edges, a handful of E2E happy paths and test data that does not rot.
Our video-call regressions were found by customers because every test needed two humans with webcams. We automated it: fake camera and microphone feeds in Chromium and Firefox, two-party calls in one Playwright test, assertions on getStats() instead of screenshots, and tc netem for packet loss and latency.
One CI run in eight failed somewhere in our checkout E2E suite, never in the same test twice. The causes were fixed sleeps, URL checks that raced navigation and text selectors that matched two buttons. Web-first assertions, role locators and traces fixed it.