Product company
Amazon
SDET-style coding, test design at scale, and ownership stories.
These are our own practice questions for the kind of QA/SDET role this company hires for. They are not the company's real interview questions. Confirm the current process on the company's official careers page.
What they tend to probe
- Coding
- Test design at scale
- Distributed systems testing
- Behavioural stories
- Operational thinking
Question 1 · Coding · Medium
Given a list of order events with timestamps, return the orders that were placed but never shipped within 24 hours.
Answer guide
Group by order id, track earliest placed and earliest shipped, compare, handle out-of-order and duplicate events. State complexity and the tests you would add.
Question 2 · Test design · Hard
Design the test strategy for an add-to-cart service that handles very high traffic.
Answer guide
Unit and contract tests, load and soak, failure injection (cache down, dependency slow), consistency of cart across devices, rollout in stages with metrics and automatic rollback.
Question 3 · Behavioural · Medium
Tell me about a time you found a serious defect late. What did you change afterwards?
Answer guide
Use a story with facts: what, impact, how it was found, the fix, and the change in process or tests so it cannot recur. Own your part.
Question 4 · Distributed · Hard
A message is delivered twice. How should the system and its tests handle it?
Answer guide
Idempotent consumers with a dedupe key, tests that replay messages, ordering and out-of-order cases, dead-letter handling, and checks on the final state.
Question 5 · Coding · Medium
Write a rate limiter and the tests that would convince you it is correct.
Answer guide
Token bucket or sliding window, an injectable clock, boundary and burst cases, concurrency, and per-user isolation.
Question 6 · Operational · Medium
How do you decide a release is safe when tests are green?
Answer guide
Canary or staged rollout, dashboards on error rate and latency, alarms, a tested rollback, and a clear owner on call.