Where should we start if our CI is already 60+ minutes?

First, profile the build. Add concurrency groups to cancel stale builds, enable dependency and Docker layer caching, and shard tests. Then split PR CI (fast, 0.3% over a week until fixed. You’ll usually cut 30–50% off without touching the codebase.

Monolith or microservices — does this change?

Same playbook. For monoliths, contracts can be module boundaries or GraphQL schema checks. Hermetic integration with Testcontainers is even easier. For microservices, double down on consumer-driven contracts and canary SLOs to kill cross-team blast radius.

How do AI-assisted changes affect testing?

Assume higher defect rates on AI-authored code. Require contracts and integration tests to pass for any PR labeled `ai-generated`. Use mutation testing spot checks and keep PR CI under 15 minutes so rework is cheap. Don’t ship AI code behind the same gates as human code without extra scrutiny.

We’re regulated (SOX/HIPAA). Can we still automate rollbacks?

Yes. Keep change logs, link PRs to tickets, sign artifacts, and gate rollbacks via policy-as-code (OPA/Conftest). Feature flags with audit trails plus Argo Rollouts give you controlled, auditable deploys with safe automatic rollback on SLO breach.

Release-engineering · Oct 17, 2025 · 9 minute read

Ship Faster, Break Less: The Test Gates That Halved Our Change Failure Rate

Automated test gates that catch regressions before they hit prod — with metrics, configs, and checklists you can copy-paste this sprint.

Alex Mercer

Partner, Release Engineering at GitPlumbers

20 years building and fixing delivery pipelines at scale. Ex-Shopify, led release at a Fortune 50 retailer during the microservices migration, and helped 30+ teams cut CFR in half without tanking velocity.

If you’re not measuring CFR, lead time, and MTTR per service in your pipeline, you’re optimizing for vibes, not outcomes.

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Ship Faster, Break Less: The Test Gates That Halved Our Change Failure Rate

Key takeaways

Implementation checklist