--- title: "Shorten deliberate test waits" description: "Reduce waits whose timing requirements are known, preserving the timeout or consistency behavior the test is intended to cover." url: https://starsling.dev/ci-playbooks/techniques/shorten-proven-test-waits canonicalUrl: https://starsling.dev/ci-playbooks/techniques/shorten-proven-test-waits --- # Shorten deliberate test waits Reduce waits whose timing requirements are known, preserving the timeout or consistency behavior the test is intended to cover. ## 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. - **[Anthropic](https://starsling.dev/ci-playbooks/anthropic#shorten-deliberate-sleeps)**: Use it when A test or a CI-run example sleeps for a fixed time only to exercise a timeout or a slow path. Check before adopting: The sleep and the timeout it triggers shrink together, so the timeout branch still runs and is asserted. - **[Mastra](https://starsling.dev/ci-playbooks/mastra#shorter-waits)**: Use it when A service exposes no usable readiness predicate and repeated conservative waits dominate tests. Check before adopting: Prefer a real completion signal; retain coverage and stress slow runners before choosing a lower bound. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Shorten deliberate test waits. Reduce waits whose timing requirements are known, preserving the timeout or consistency behavior the test is intended to cover. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/shorten-proven-test-waits.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. ### Anthropic: Shorten deliberate sleeps in tests and examples The Claude Agent SDK's error-handling example, which CI runs on every pull request, asked for a 60-second sleep to trigger a 10-second timeout. The change asks for 5 seconds and times out at 3, so the timeout path still runs. Evidence: Estimate The PR's estimate is that the shorter sleep removes 50+ seconds from the examples job; the same PR also raises that step's timeout. ([Source](https://github.com/anthropics/claude-agent-sdk-python/pull/760)) Use it when: A test or a CI-run example sleeps for a fixed time only to exercise a timeout or a slow path. Before applying it: The sleep and the timeout it triggers shrink together, so the timeout branch still runs and is asserted. [Read more in the Anthropic playbook](https://starsling.dev/ci-playbooks/anthropic#shorten-deliberate-sleeps) [Primary source](https://github.com/anthropics/claude-agent-sdk-python/pull/760) ### Mastra: Shorten only waits whose consistency is already proved Chroma reduced 80 fixed 2-second waits, from three call sites, to 200 milliseconds; Couchbase reduced per-operation waits while adding a service readiness probe. Evidence: Estimate Chroma’s PR estimates the Run Chroma tests step drops from 160 seconds of sleeping to about 16 seconds. ([Source](https://github.com/mastra-ai/mastra/pull/13866)) Use it when: A service exposes no usable readiness predicate and repeated conservative waits dominate tests. Before applying it: Prefer a real completion signal; retain coverage and stress slow runners before choosing a lower bound. [Read more in the Mastra playbook](https://starsling.dev/ci-playbooks/mastra#shorter-waits) [Primary source](https://github.com/mastra-ai/mastra/pull/13866) ## 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 ### [Complete the fixture before its timeout fires](https://starsling.dev/ci-playbooks/techniques/finish-fixtures-before-timeout) Exercise the event that advances the test, so it stops waiting on the timer that rescues it. 1 implementation · 1 company (Uber) ### [Wait for observable readiness instead of sleeping](https://starsling.dev/ci-playbooks/techniques/poll-readiness) Poll the service or state the test actually needs, with a bounded timeout and useful failure output. 4 implementations · 3 companies (Mastra, Stripe, Uber) ### [Balance test work across shards](https://starsling.dev/ci-playbooks/techniques/balance-test-shards) Use measured runtimes or smaller test files to reduce the slowest shard, which determines when the suite finishes. 4 implementations · 4 companies (Linear, OpenAI, Ramp, 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. ### [Cut repeated test setup](https://starsling.dev/best-practices/github-actions/cut-repeated-test-setup) Move shared fixture work out of individual test cases and keep necessary cleanup. ### [Shard tests across parallel jobs](https://starsling.dev/best-practices/github-actions/shard-tests) Split a long suite with a matrix and your test framework’s sharding support. ### [Diagnose slow tests in CI](https://starsling.dev/github-actions/problems/slow-tests) Check common causes in order and confirm each with workflow evidence. ### [Optimize Playwright tests](https://starsling.dev/github-actions/optimizations/optimize-playwright) Choose trace and video retention and install the browsers your suite uses. ### [Make Vitest run mode explicit](https://starsling.dev/github-actions/optimizations/optimize-vitest) Pin run mode to the test command and bound the job with a timeout.