Build before starting the emulator

Compile the app first, then boot the emulator and install the finished build.

Prompt

Evaluate and apply this CI technique to my repository: Build before starting the emulator.

Compile the app first, then boot the emulator and install the finished build.

Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/avoid-emulator-build-contention.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.

View all playbooks

How Stripe used this technique

Read what Stripe changed and follow the original sources.

Build before starting the emulator

Stripe React Native moved app compilation ahead of emulator startup and installed the finished APK. It also built only the emulator’s x86_64 architecture and removed a disk-cleanup step, which the author estimated at 20 seconds.

Use it when: Compilation runs while an emulator competes for the same CPU and memory.
Before applying it: Keep the device and ABI coverage other lanes require, and measure disk headroom before removing cleanup.

How Stripe used this technique

Build before starting the emulator

Related techniques

Build only what the test or analysis consumes

Install a pinned tool release

Release query results before they become a timeout

Company Playbooks

Related guides

Filter workflows by changed files

Cancel superseded CI runs