- All playbooks
- Replay fixed evaluations before merging agent changes
Replay fixed evaluations before merging agent changes
Run repeatable scenarios or a golden dataset on changes to agent behavior so regressions are visible before merge.
How companies used this technique
Read what each company changed and follow the original sources.
Gate agent changes on a simulated, fixture-backed eval run
Translated to GitHub Actions
- What DoorDash built
- For Ask DoorDash, a simulated user drives fixed scenarios against recorded tool fixtures and an LLM judge scores each session.
- Your GitHub Actions version
- A required check that replays fixed scenarios against recorded fixtures and gates the change on the rubric pass rate.
For Ask DoorDash, a simulated user drives fixed scenarios against recorded tool fixtures, and an LLM judge calibrated against human reviewers scores each session on the same rubric used in production. Generating the 400 conversations of a comprehensive sweep by hand would take more than six hours, and the simulator reduces that generation step to about 20 minutes, which makes it practical to evaluate changes as large as a base-model migration. DoorDash Assistant changes are gated on the rubric pass rate, and DoorDash's carousel generator holds every prompt revision to launch thresholds set before evaluation.
- Use it when
- Changes to prompts, models or agent code ship after a manual check, or after an eval run too slow to run on every change.
- Before applying it
- Fixtures freeze the world the agent sees; refresh them from production traces so the gate keeps testing current behavior.
- GitHub Actions adaptation
- Compare the source system with your own workflow before applying this translation.
Replay a golden dataset on every pull request
Stripe engineers recommend a golden dataset for pull requests: a curated set of inputs and expected outputs that covers common flows, qualification boundaries and past incidents. In the workflow they describe, CI runs the candidate implementation against the inputs on every pull request and blocks the build on an unexpected difference, which tells reviewers whether observable behavior changed and where. When an incident exposes a missed edge case, the case can be preserved in the dataset. For larger changes, a Spark job replays historical inputs through the same decision logic and compares the old and new implementations.
- Use it when
- A service's output depends on many interacting rules, and unit tests cover single rules but not realistic combinations.
- Before applying it
- Keep unit tests for small, hand-built cases. Reduce each input to the fields the behavior needs, and replace sensitive identifiers with stable test identifiers.
Company Playbooks
- Read Anthropic’s playbookRun only affected tests
- Read DoorDash’s playbookRun build and test in parallel, sharded across CI agents
- Read Linear’s playbookBenchmark the same job on faster hardware
- Read Mastra’s playbookStarSling runners for the slowest test workflow
- Read OpenAI’s playbookRank CI fixes by the minutes they save
- Read Ramp’s playbookMove a CPU-bound test suite to a faster CPU
- Read Shopify’s playbookLet an agent iterate against one CI metric
- Read Spotify’s playbookBuild arm64 on native arm64 runners
- Read Stripe’s playbookRun only the tests a change can reach
- Read Uber’s playbookBuild the merge-queue speculations most likely to be needed