CI pipelines

CI has one job: tell you quickly and reliably whether a change is safe to merge. Two failure modes destroy that, and both end the same way — with people ignoring the pipeline.

Too slow and people stop waiting, merging on a green they did not see. Unreliable and people re-run until it passes, which trains everyone to treat a red build as noise. A flaky pipeline is worse than no pipeline, because it consumes the attention a real failure needs.

1. Order stages by speed, fail fast

Run the cheapest checks first so a typo does not wait behind an integration suite:

1. Lint and format — seconds
2. Type check and compile — under a minute
3. Unit tests — a few minutes
4. Integration tests — longer, needs services
5. End-to-end — slowest, smallest set
6. Build artifacts — only if everything passed