Software Engineer interview
at Stripe.

Tell-me-about-a-time stories on ownership, conflict, and impact — scored against this company's real values.

1. 01 Tell me about a time you shipped something that directly removed friction for a developer or user, and how you knew it mattered to them.
2. 02 Describe a bug or incident in production that you owned end-to-end, including how you communicated it and prevented recurrence.
3. 03 Walk me through a time you disagreed with a technical decision and what rigorous argument you made to change it.
4. 04 Tell me about a time you amplified a teammate's work or improved the team rather than just optimizing your own output.

The hard screen for the craft itself — talked through out loud, not whiteboarded in your head.

1. 01 Given an unfamiliar repository with a failing test, walk me through how you'd diagnose the root cause before attempting a fix.
2. 02 Using only the API documentation provided, build a small integration that receives webhooks, verifies their signatures, and processes events idempotently.
3. 03 How would you implement an idempotency-key mechanism so that a retried payment request never double-charges a customer?
4. 04 You're given a function that moves money between two accounts; identify the concurrency and rounding edge cases and make it correct.

Open-ended design of the systems this company actually runs, with the interviewer probing your tradeoffs.

1. 01 Design an idempotent payments API that safely handles client retries and network failures without double-charging.
2. 02 Design a double-entry ledger that records every money movement with atomic balanced writes and supports reconciliation.
3. 03 Design a webhook delivery system with retries, exponential backoff, ordering, and signature verification.
4. 04 Design a system that processes card payments with at-least-once semantics while guaranteeing exactly-once financial effects.