The test-design exercise
"How would you test a login page?" or a lift, or a vending machine. Interviewers want categories, not a stream of cases. A structure that works:
- Clarify scope first. Web or mobile? Which browsers? Is there two-factor? Are we testing the API too? Asking this is itself scored.
- Functional, positive. The paths that should work.
- Functional, negative. Wrong password, empty fields, locked account, expired session.
- Boundary and equivalence. Field length limits, exactly at and either side of them.
- Security. Injection attempts, rate limiting, whether errors leak whether an account exists.
- Usability and accessibility. Keyboard only, screen reader, error message clarity.
- Compatibility. Browsers, devices, screen sizes.
- Performance. Behaviour under load, slow network, offline.
Automation questions
- What belongs in automation and what should stay manual? Expect to defend a line rather than say everything.
- The test pyramid - and why heavy end-to-end suites become a problem.
- How do you handle flaky tests? The expected answer is that you treat flakiness as a defect, not as something to retry around.
- Explicit versus implicit waits, and why sleeps in tests are a smell.
- How do you choose selectors so tests do not break on every UI change?
- How would you test an API without a UI? Status codes, schema, auth, error cases, idempotency.
Process and judgement
- A bug is found in production. What is your response, beyond fixing it?
- How do you write a bug report that a developer can act on without asking you anything?
- Severity versus priority, with an example where they differ.
- The release is tomorrow and testing is not finished. What do you do?
- How do you decide a feature is ready to ship?
These are judgement questions. The honest answers - that you quantify risk and escalate rather than quietly approve - score better than heroics.
Manual QA versus SDET
| Manual / QA analyst | SDET | |
|---|---|---|
| Core round | Test design and exploratory testing | Test design plus real coding |
| Coding depth | Light, often none | Close to a software engineer round |
| Framework questions | Using them | Building and maintaining them |
| Also expect | Domain knowledge, process | CI integration, test infrastructure |
Where CoPilot Interview fits
Disclosure: we build an interview assistant, so treat this as a disclosed pitch. CoPilot Interview is a native Windows and macOS app that puts suggested answers on your own screen in about two seconds, across coding, system design and behavioral rounds, with a permanent free tier that needs no credit card.
There is a role page at QA interview help.
Frequently asked questions
What questions are asked in a QA engineer interview?
Nearly every loop includes a test-design exercise - how would you test this - plus automation questions on the test pyramid, flaky tests and selector strategy, and judgement questions about severity versus priority and what to do when a release date arrives before testing finishes.
How do you answer 'how would you test a login page'?
Give categories rather than a list of cases: positive and negative functional paths, boundary and equivalence, security, usability and accessibility, compatibility and performance. Then prioritise unprompted - saying which five you would run with two hours is the strongest move in the round.
What is the difference between a QA and an SDET interview?
SDET loops include a genuine coding round close to a software engineer's, and ask about building and maintaining test frameworks and CI infrastructure. Manual QA loops weight test design, exploratory testing, domain knowledge and process, with light or no coding.
How should you answer questions about flaky tests?
Treat flakiness as a defect to be diagnosed rather than something to retry around. Strong answers cover identifying the source - timing, test interdependence, shared state - replacing sleeps with explicit waits, and quarantining rather than ignoring.
Walk into the round with a second pair of eyes
CoPilot Interview is a native Windows and macOS app that puts suggested answers on your own screen in about two seconds, across coding, system design and behavioral rounds. The free tier is permanent: 15 minutes a day, no credit card.
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