--- title: "Let shared packages without a build step stay cacheable" description: "Treat a package with nothing to build as cacheable, so its dependents spread across every CI agent." url: https://starsling.dev/ci-playbooks/techniques/uncluster-no-op-projects canonicalUrl: https://starsling.dev/ci-playbooks/techniques/uncluster-no-op-projects --- # Let shared packages without a build step stay cacheable Treat a package with nothing to build as cacheable, so its dependents spread across every CI agent. ## How to choose an approach This technique currently has one documented company example. Validate its prerequisites, tradeoffs and original CI environment against your repository before adapting it. - **[DoorDash](https://starsling.dev/ci-playbooks/doordash#uncluster-no-op-projects)**: Use it when A distributed or sharded build keeps work on one machine whenever it depends on a package that produces no output. Check before adopting: A no-op has nothing to restore, so this holds only for packages with no build or test script; a package that writes output still needs its outputs declared. Adapted for GitHub Actions; compare the original system with yours. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Let shared packages without a build step stay cacheable. Treat a package with nothing to build as cacheable, so its dependents spread across every CI agent. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/uncluster-no-op-projects.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 DoorDash used this technique Read what DoorDash changed and follow the original sources. ### DoorDash: Let shared packages without a build step stay cacheable **Translated to GitHub Actions** - What DoorDash built: DoorDash builds its web monorepo with Rush cobuilds, where each CI agent picks up any task whose dependencies are done. - Your GitHub Actions version: Split the build across parallel jobs by the project graph, and let projects with no build output run as separate tasks. DoorDash builds its web monorepo with Rush cobuilds, where each CI agent picks up any task whose dependencies are done. Cobuilds kept a project and its dependents on one agent when the project had no cacheable output, and DoorDash's shared rigs and ESLint profile have no build step, so nearly every project landed in one cluster. DoorDash contributed the fix upstream: a no-op operation now counts as cacheable. With the clusters gone, DoorDash cut its cobuild agents from ten to five, and cobuilds used all five. Evidence: Documented technique Use it when: A distributed or sharded build keeps work on one machine whenever it depends on a package that produces no output. Before applying it: A no-op has nothing to restore, so this holds only for packages with no build or test script; a package that writes output still needs its outputs declared. GitHub Actions adaptation: Compare the source system with your own workflow before applying this translation. [Read more in the DoorDash playbook](https://starsling.dev/ci-playbooks/doordash#uncluster-no-op-projects) [Primary source](https://careersatdoordash.com/blog/how-doordash-slashed-web-developer-build-times/) ## 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) ### [Overlap independent setup with explicit joins](https://starsling.dev/ci-playbooks/techniques/overlap-independent-setup) Pull images while dependencies install, and wait for each background step explicitly. 1 implementation · 1 company (Stripe) ## 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.