Starting Point

• Releases stalled because critical flows required manual end-to-end verification.
• Existing tests were brittle and tightly coupled to implementation details.
• Team wanted confidence without adding headcount.

What We Built

• Risk-prioritized test pyramid with contract tests between services.
• Deterministic test fixtures and resilient selectors for critical flows.
• Scope focused on top revenue paths first; long-tail admin flows deferred.

How AI Changed the Outcome

• AI drafted baseline test cases from production bug history.
• LLM-assisted mutation report triage identified weak assertions in high-risk paths.
• Automated review checks blocked low-signal AI-generated test additions.

What We’d Do Differently

We should have introduced synthetic monitoring earlier; waiting until week 7 delayed validation for production-like timing failures.