Pipeline Fail-Fast Patterns

Fail fast, signal early.

Why fail fast

A 30-minute pipeline that fails at minute 28 wastes 28 minutes.

Fail-fast: cheap checks first, expensive checks last. The pipeline aborts as soon as a check fails.

Reduces feedback time, reduces compute cost, reduces engineer wait time.

Stage ordering

Lint and format: 30 seconds.

Type check: 1-3 minutes.

Unit tests: 3-10 minutes.

Integration tests: 10-30 minutes.

Security scans, image builds, deploy: only if everything above passed.

Parallel where it helps

Lint, type check, and unit tests can run in parallel for different modules.

Don't parallelize at the cost of clarity. A 50-job matrix that nobody understands is worse than a 5-job sequential pipeline.

Cap parallelism. CI runners are not infinite; over-parallelizing hits queueing limits.

Fast feedback to author

On failure, notify the PR author immediately. Don't wait for the full pipeline to finish.

Slack notification with the failure stage and a link to the log line.

Annotate the PR with the failure: GitHub Checks, GitLab merge request comments.

How to roll this out

Audit current pipeline for stages that always fail late. Move fast checks earlier.

Set a target: 90% of failures detected in the first 5 minutes.

Track time-to-failure as a CI metric. Improvements compound across thousands of builds.