Delivery Playbook · Craft
Testing
The kinds of testing we do, who does each, and how defects are reported and closed.
Owner: CTO · Last reviewed: · Next review: 28 April 2027
Testing is how we prove that the software works before it reaches your users. We test in layers, and each layer has an owner, so nothing depends on one person remembering to check.
The layers
| Test | Who owns it | Purpose |
|---|---|---|
| Unit | Developers | Check the smallest parts while the story is being built. Acceptance criteria are covered by unit tests |
| Component and functional | QC | Check each function against its requirements |
| Smoke and sanity | QC | Check that a new build is stable enough to test further |
| Integration (end to end) | QC | Check that the parts work together across the whole flow |
| Data validity | QC | Check that data is correct and stays correct |
| Regression | QC | Check that new work has not broken what already worked |
| Acceptance | QC with the customer's stakeholders | Confirm the solution is correct before release |
Testing often starts by hand and moves to automation as scenarios stabilize. Automation is added where a check will be repeated many times, such as regression.
When testing counts as finished
Each layer has an exit rule. For example, regression and acceptance testing finish when no top-priority or high-priority defects remain open, and lower-priority defects are written down.
How a defect is reported
- A summary of the exact problem
- Exact steps to reproduce it
- What happened and what was expected
- A screenshot or video, and the version where it was found
- A severity set by the reporter. Priority is set by the Delivery Manager or product owner
A fixed defect goes to code review, then to retesting. It is closed only when the tester confirms the fix and the surrounding area still works.
Testing AI-written code
AI can write tests quickly, and it can write tests that pass for the wrong reason. We therefore check that AI-written tests fail when the code is deliberately made wrong.
Related
Craft
Code review
What happens between a change being written and being merged, and what a reviewer actually checks.
Craft
How an engineer reads AI-written code
The extra care we take with code that an AI tool wrote, and why the engineer stays responsible for it.
Working agreements
Definition of ready and done
The entry and exit checks that keep stories small, clear and truly finished.
