Share setup across small checks
Combine compatible short checks so checkout and dependency setup do not dominate the time spent doing useful work.
How companies used this technique
Read what each company changed and follow the original sources.
Pay setup twice instead of seven times
Linear consolidated seven small independent checks into two jobs and ran their tasks concurrently. Based on June usage, the change saved roughly 87,000 runner-minutes per month, equivalent to 11.8% of Linear’s total CI usage.
- Use it when
- Independent short jobs repeat more checkout and dependency setup than useful work.
- Before applying it
- Keep every check and its exit status, and keep the remaining critical path as short as before.
Company Playbooks
- Read Anthropic’s playbookRun only affected tests
- Read DoorDash’s playbookRun build and test in parallel, sharded across CI agents
- Read Linear’s playbookBenchmark the same job on faster hardware
- Read Mastra’s playbookStarSling runners for the slowest test workflow
- Read OpenAI’s playbookRank CI fixes by the minutes they save
- Read Ramp’s playbookMove a CPU-bound test suite to a faster CPU
- Read Shopify’s playbookLet an agent iterate against one CI metric
- Read Spotify’s playbookBuild arm64 on native arm64 runners
- Read Stripe’s playbookRun only the tests a change can reach
- Read Uber’s playbookBuild the merge-queue speculations most likely to be needed