--- title: "Package once, and build full installers after merge" description: "Drop the build step that packaging repeats, and build the unpacked app pull requests test." url: https://starsling.dev/ci-playbooks/techniques/package-once canonicalUrl: https://starsling.dev/ci-playbooks/techniques/package-once --- # Package once, and build full installers after merge Drop the build step that packaging repeats, and build the unpacked app pull requests test. ## 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#package-once)**: Use it when A job builds explicitly before a packaging or test command that builds again, or pull requests build release artifacts that no test reads. Check before adopting: Read the wrapper scripts before removing a build step. The full installers still need a post-merge run that someone watches. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Package once, and build full installers after merge. Drop the build step that packaging repeats, and build the unpacked app pull requests test. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/package-once.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: Package once, and build full installers after merge The desktop job ran a Build step and then packaging, which runs the same electron-vite build again. The PR removed the standalone Build step. Pull requests now package the unpacked app that the end-to-end journeys consume; pushes to main still build and inspect the full installers. Evidence: Source PR/commit evidence Use it when: A job builds explicitly before a packaging or test command that builds again, or pull requests build release artifacts that no test reads. Before applying it: Read the wrapper scripts before removing a build step. The full installers still need a post-merge run that someone watches. [Read more in the DoorDash playbook](https://starsling.dev/ci-playbooks/doordash#package-once) [Primary source](https://github.com/doordash-oss/agentic-orchestrator/pull/139) ## 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 ### [Move selected heavy checks after merge](https://starsling.dev/ci-playbooks/techniques/defer-heavy-validation) Keep a deliberately chosen pull request gate and schedule heavier validation after merge, with explicit ownership of the resulting risk. 2 implementations · 2 companies (OpenAI, Shopify) ### [Remove repeated build steps](https://starsling.dev/ci-playbooks/techniques/avoid-duplicate-builds) Trace artifact producers and consumers so package, release, or test stages reuse work instead of triggering the same build again. 4 implementations · 3 companies (Mastra, OpenAI, Spotify) ### [Run shared validation once](https://starsling.dev/ci-playbooks/techniques/avoid-duplicate-validation) Remove overlapping task or matrix invocations that perform the same check on the same inputs. 4 implementations · 3 companies (DoorDash, Mastra, 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. ### [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.