--- title: "Share setup across small checks" description: "Combine compatible short checks so checkout and dependency setup do not dominate the time spent doing useful work." url: https://starsling.dev/ci-playbooks/techniques/share-small-job-setup canonicalUrl: https://starsling.dev/ci-playbooks/techniques/share-small-job-setup --- # Share setup across small checks Combine compatible short checks so checkout and dependency setup do not dominate the time spent doing useful work. ## How to choose an approach Compare the examples by repository setup, prerequisites, and risks before adopting one. Each company implemented this in its own environment; measure each change against your own baseline. - **[Linear](https://starsling.dev/ci-playbooks/linear#batch-short-checks)**: Use it when Independent short jobs repeat more checkout and dependency setup than useful work. Check before adopting: Keep every check and its exit status, and keep the remaining critical path as short as before. - **[Stripe](https://starsling.dev/ci-playbooks/stripe#share-small-job-setup)**: Use it when Independent small jobs spend more time on repeated setup than on their own work. Check before adopting: A combined job runs its parts in sequence, so compare the new critical path with the setup saved. Keep required-check names through an aggregator, and split again when a combined job becomes the long pole. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Share setup across small checks. Combine compatible short checks so checkout and dependency setup do not dominate the time spent doing useful work. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/share-small-job-setup.md Inspect this repository’s CI workflows, build and test commands, dependencies, and recent run timings. Identify where this technique applies and explain the expected benefit using this repository’s evidence. Measure a baseline from recent comparable runs: elapsed time, queue time, runner minutes and failures where available. If data is unavailable, say what cannot be measured. Compare relevant company approaches, checking prerequisites, platform differences and tradeoffs. Rank applicable options by evidence, fit and measurable opportunity; do not present company results as predictions for this repo. Recommend the smallest safe change, show what checks and fallback paths remain, and ASK ME WHICH CHANGE TO APPROVE BEFORE EDITING ANY FILES. Only after approval, work on a new feature branch, make one reversible change, and open a reviewable pull request. Never merge or push to a default or protected branch. Keep required checks, test coverage, deployment and release behavior intact. Validate the change and compare equivalent runs where possible; report limitations and what should be monitored after merge. ```` ## How companies used this technique Read what each company changed and follow the original sources. ### Linear: 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. Evidence: Documented technique 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. [Read more in the Linear playbook](https://starsling.dev/ci-playbooks/linear#batch-short-checks) [Primary source](https://linear.app/now/ci-bottleneck-reworked#batch-short-checks-into-fewer-jobs) ### Stripe: Share setup across compatible small checks Stripe iOS combined several pairs of small jobs, including snapshot recording with the localization upload and the Connect and Crypto UI tests, so each pair pays for setup once. Evidence: Source PR/commit evidence Use it when: Independent small jobs spend more time on repeated setup than on their own work. Before applying it: A combined job runs its parts in sequence, so compare the new critical path with the setup saved. Keep required-check names through an aggregator, and split again when a combined job becomes the long pole. [Read more in the Stripe playbook](https://starsling.dev/ci-playbooks/stripe#share-small-job-setup) [Primary source](https://github.com/stripe/stripe-ios/pull/6969) ## CI optimization is continuous work. Apply this technique yourself, or use StarSling Runners for faster GitHub Actions and optional agent-driven optimization PRs, which teams on eligible paid plans can turn on. [Get self-improving CI](https://starsling.dev/products/runners) ## Related techniques ### [Clean up independent test resources concurrently](https://starsling.dev/ci-playbooks/techniques/parallel-cleanup) Independent index deletions do not need a separate serial wait per index. 1 implementation · 1 company (Mastra) ### [Compress release artifacts in parallel](https://starsling.dev/ci-playbooks/techniques/parallel-packaging) Compress independent release binaries two at a time. 1 implementation · 1 company (OpenAI) ### [Let shared packages without a build step stay cacheable](https://starsling.dev/ci-playbooks/techniques/uncluster-no-op-projects) Treat a package with nothing to build as cacheable, so its dependents spread across every CI agent. 1 implementation · 1 company (DoorDash) ## Company Playbooks ### [Anthropic](https://starsling.dev/ci-playbooks/anthropic) Run only affected tests ### [DoorDash](https://starsling.dev/ci-playbooks/doordash) Run build and test in parallel, sharded across CI agents ### [Linear](https://starsling.dev/ci-playbooks/linear) Benchmark the same job on faster hardware ### [Mastra](https://starsling.dev/ci-playbooks/mastra) StarSling runners for the slowest test workflow ### [OpenAI](https://starsling.dev/ci-playbooks/openai) Rank CI fixes by the minutes they save ### [Ramp](https://starsling.dev/ci-playbooks/ramp) Move a CPU-bound test suite to a faster CPU ### [Shopify](https://starsling.dev/ci-playbooks/shopify) Let an agent iterate against one CI metric ### [Spotify](https://starsling.dev/ci-playbooks/spotify) Build arm64 on native arm64 runners ### [Stripe](https://starsling.dev/ci-playbooks/stripe) Run only the tests a change can reach ### [Uber](https://starsling.dev/ci-playbooks/uber) Build the merge-queue speculations most likely to be needed ## Related guides Implementation guides for this technique. ### [Shard tests across parallel jobs](https://starsling.dev/best-practices/github-actions/shard-tests) Use native test sharding and a job matrix to divide a long suite. ### [Parallelize independent jobs](https://starsling.dev/github-actions/optimizations/parallelize-independent-jobs) Run independent validation lanes concurrently and keep genuine job dependencies. ### [Bound runner jobs with timeouts](https://starsling.dev/best-practices/github-actions/bound-job-timeouts) Set job and step timeouts using expected durations and failure behavior. ### [Right-size GitHub Actions runners](https://starsling.dev/best-practices/github-actions/right-size-runners) Match runner resources to the workload and compare equivalent runs.