--- title: "Install and build only the workspace packages a job uses" description: "Scope dependency installation and builds to the package or lane under test, including its actual dependencies." url: https://starsling.dev/ci-playbooks/techniques/scope-workspace-builds canonicalUrl: https://starsling.dev/ci-playbooks/techniques/scope-workspace-builds --- # Install and build only the workspace packages a job uses Scope dependency installation and builds to the package or lane under test, including its actual dependencies. ## 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#filtered-installs)**: Use it when A job’s dependency closure is smaller than the workspace. Check before adopting: Include transitive dependencies and generated prerequisites. - **[Mastra](https://starsling.dev/ci-playbooks/mastra#scope-build)**: Use it when A narrow test job pays for unrelated workspace builds. Check before adopting: Trace transitive dependencies and generated artifacts. Before moving a build out of a gate, confirm another required check still runs it. - **[Shopify](https://starsling.dev/ci-playbooks/shopify#scope-package-lanes)**: Use it when A monorepo runs one long sequential job that builds and tests every package on every run. Check before adopting: A new package has to be added to a lane, and each lane repeats install and setup. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Install and build only the workspace packages a job uses. Scope dependency installation and builds to the package or lane under test, including its actual dependencies. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/scope-workspace-builds.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: Install or build only the workspace packages this step needs Linear restricted its API test install to the API package and its dependencies, which cut pnpm install from 44-73 seconds to 16-18 seconds, then applied the same filter to API-adjacent jobs. In its public SDK, the release-preparation job builds only the package schema generation imports before updating the schema. Evidence: Documented technique Use it when: A job’s dependency closure is smaller than the workspace. Before applying it: Include transitive dependencies and generated prerequisites. [Read more in the Linear playbook](https://starsling.dev/ci-playbooks/linear#filtered-installs) [Primary source](https://linear.app/now/ci-bottleneck-reworked#install-only-the-dependencies-each-job-needs) ### Mastra: Build only the dependencies the test consumes The memory test build replaced the entire stores wildcard with libsql, pg and upstash while retaining its other required packages. Another change moved a docs-server build out of the changed-test gate. Evidence: Source PR/commit evidence Use it when: A narrow test job pays for unrelated workspace builds. Before applying it: Trace transitive dependencies and generated artifacts. Before moving a build out of a gate, confirm another required check still runs it. [Read more in the Mastra playbook](https://starsling.dev/ci-playbooks/mastra#scope-build) [Primary source](https://github.com/mastra-ai/mastra/pull/22381) ### Shopify: Give each CI lane a defined package set The app libraries ran everything in ci.yml in sequence, once per Node version. Shopify/shopify-app-js#2777 split that into a lint job and three package-family jobs that run in parallel; each builds its own dependency closure with pnpm filters and tests only its family. The pattern match is partial: the filters scope each lane, and the speedup comes from running the lanes in parallel. Evidence: Source PR/commit evidence The PR reports CI running in about 5 minutes against about 11 before. ([Source](https://github.com/Shopify/shopify-app-js/pull/2777)) Use it when: A monorepo runs one long sequential job that builds and tests every package on every run. Before applying it: A new package has to be added to a lane, and each lane repeats install and setup. [Read more in the Shopify playbook](https://starsling.dev/ci-playbooks/shopify#scope-package-lanes) [Primary source](https://github.com/Shopify/shopify-app-js/pull/2777) ## 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 ### [Reduce the setup floor before increasing shard count](https://starsling.dev/ci-playbooks/techniques/setup-cost-limits-sharding) Each extra shard repeats checkout, dependencies and container setup. 1 implementation · 1 company (Linear) ### [Package once, and build full installers after merge](https://starsling.dev/ci-playbooks/techniques/package-once) Drop the build step that packaging repeats, and build the unpacked app pull requests test. 1 implementation · 1 company (DoorDash) ### [Skip jobs whose inputs have not changed](https://starsling.dev/ci-playbooks/techniques/skip-unaffected-jobs) Gate expensive workflows and jobs on the files they consume, keeping required check behavior intact. 7 implementations · 6 companies (Anthropic, DoorDash, Mastra, OpenAI, Shopify, 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. ### [Cancel superseded CI runs](https://starsling.dev/best-practices/github-actions/cancel-superseded-runs) Use concurrency groups to keep PR verification focused on the latest commit. ### [Build and test only what changed](https://starsling.dev/best-practices/github-actions/build-only-affected) Scope work with your dependency graph and keep a full-run fallback. ### [Filter workflows by changed files](https://starsling.dev/best-practices/github-actions/path-filter-workflows) Use paths and job conditions while keeping required checks reporting. ### [Cut CI queue time](https://starsling.dev/best-practices/github-actions/cut-queue-time) Measure waiting time and identify concurrency or capacity constraints.