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Stripe·Software Engineer·Technical Phone Screen·Intermediate

IntermediatePrefer not to say
May 2026Remote

Summary

Stripe debugging round where they hand you a broken codebase and a pile of failing tests and basically just watch how you work through it. Less about knowing the answer upfront and more about whether your process is clean under pressure.

Questions Asked (1)

Q1

You're given a small existing codebase with failing tests. Walk through debugging it: identify the bugs, fix them, and iterate until the tests pass, while narrating your reasoning at each step.

Root Cause AnalysisTechnical Trade-offs
Author's notes

The part that tripped me up was the narration requirement.

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AI HintsAI Generated

Suggested Approach

Start by running the tests to see the failures, then systematically trace each failure to its root cause using the error messages and code inspection. Fix one bug at a time, re-running tests after each change to confirm progress and avoid introducing new issues. Narrate your hypotheses, the evidence you gather, and your reasoning for each fix.

Pro tip: Before diving into fixes, take a moment to understand the codebase's structure and the test suite's purpose—this context often reveals patterns behind the bugs and shows you prioritize understanding over speed.

1. Reproduce and Understand Failures

Run the test suite to see all failures, then read the error messages and stack traces carefully to form initial hypotheses about what's wrong.

2. Isolate and Diagnose Each Bug

For each failure, inspect the relevant code, add debug prints or use a debugger if needed, and trace the logic to pinpoint the exact cause.

3. Fix and Verify Incrementally

Make a minimal fix for one bug, re-run the tests to confirm it resolves that failure and doesn't break others, then move to the next.

4. Iterate and Refactor if Needed

After all tests pass, review your changes for quality, consider edge cases, and ensure the fixes are clean and maintainable.

Key Points to Mention

  • Reading and interpreting error messages and stack traces effectively
  • Using a systematic debugging approach (e.g., binary search, divide and conquer)
  • Writing or modifying tests to confirm hypotheses
  • Considering edge cases and potential side effects of fixes
  • Communicating reasoning clearly and concisely while debugging
  • Prioritizing fixes based on impact and dependencies

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.