Shift-left: move testing earlier in development cycle.
Old way: dev writes code; QA tests after; defects late, expensive.
New way (shift-left): testing happens during dev. Defects caught early; cheap.
Practices:
1. Test cases written before code.
- During requirements / Discovery.
- Forces clarity.
- Devs build to known criteria.
2. Pair dev + QA.
- Together for hard problems.
- Knowledge sharing.
3. Test-Driven Development (TDD).
- Write test; implement; refactor.
4. Continuous testing.
- CI/CD runs tests on every commit.
- Fast feedback to developers.
5. Devs write more tests.
- Apex unit tests by devs (mandatory).
- LWC Jest tests by devs.
6. Code review focuses on testability.
- Reviewers ask: "is this tested?"
7. Static analysis early.
- PMD, ESLint, security scanners.
- Issues identified pre-merge.
8. Lint rules in IDE.
- Issues caught while typing.
9. Pre-commit hooks.
- Tests run locally before commit.
Benefits:
- Earlier defects = cheaper to fix.
- Faster feedback = faster delivery.
- Quality culture = team-wide ownership.
Anti-patterns:
- QA at end — old waterfall mode.
- QA-only quality — devs disengaged.
- No automation — slow feedback.
Salesforce specifics:
- Apex tests mandatory at deploy.
- Jest for LWC.
- DX-driven testing — local + CI.
Senior QA insight: shift-left is a culture change. Tools matter; mindset matters more.
The senior framing: quality is everyone's job. Shift-left makes it real.