How do we start if our current e2e suite is slow and flaky?

Freeze scope. Keep 2–5 smoke tests that mirror top user paths. Move the rest down to unit/contract/integration. Introduce Pact for interfaces, WireMock for dependencies, and add a flake quarantine with ownership and SLAs. Your PR gates should drop under 15 minutes before you touch anything else.

Do we need microservices to use contract tests?

No. Contracts work for modules inside a monorepo (think “module A depends on module B”). Use Pact or simple JSON Schema checks. The point is decoupling and making interfaces explicit and verifiable in CI.

How do we measure DORA metrics from CI?

Emit events from your pipeline: PR open → merge time (lead time), deployment outcomes (CFR), incident start/resolve times (MTTR). Ship them to Prometheus/Datadog via a small script. Many shops also tag releases in Git and read from incident tooling (PagerDuty) to compute MTTR.

What about AI-generated tests?

They can bootstrap unit coverage, but don’t let them write your contracts or e2e. Keep humans in the loop for interface semantics and production guardrails. We’ve seen AI add brittle tests that inflate coverage but don’t reduce CFR.

Release-engineering · Oct 4, 2025 · 10 minute read

The CI Gates That Catch Regressions Early (Without Killing Lead Time)

If your pipeline doesn’t protect change failure rate, lead time, and MTTR, you’re gambling. Here’s the automated testing strategy I’ve seen work at scale—complete with configs and a checklist your team can actually follow.

Alex Mercer

Principal Release Engineer, GitPlumbers

20 years shipping and rescuing releases at scale—Jenkins before it was cool, Kubernetes before it was expensive, and enough 2 a.m. rollbacks to know what actually works.

If it isn’t protecting CFR, lead time, or MTTR, it’s just noise in your pipeline.

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The CI Gates That Catch Regressions Early (Without Killing Lead Time)

Key takeaways

Implementation checklist