What does a professional testing strategy look like?

Goal. Fast, trustworthy feedback that a change is safe to ship.

Strategy

• Follow the test pyramid: many fast unit tests, fewer integration tests, a small set of end-to-end tests on critical journeys
• TDD / BDD where the logic is complex — write the failing test first, or specify behaviour in business language
• Test behaviour, not implementation; use mocks sparingly and prefer real databases in integration tests
• Coverage is a signal, not a goal — review what is *not* covered, especially authorization and money paths
• Non-functional tests: performance, security, accessibility and resilience
• Eliminate flaky tests immediately; a flaky suite trains people to ignore failures
• Regression tests for every production bug

Gate every merge on automated tests in CI.