← Stripe Interview Insights

Stripe·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Jul 2026

Summary

Stripe technical screen for a software engineer role. The whole round was built around debugging a chain of five API calls where the first two pass and the last three break in various ways. Pretty unusual format but kind of makes sense for a payments company.

Questions Asked (1)

Q1

You are given a sequence of five API requests against a live HTTP service. The first two succeed with 200s, but the next three return non-2xx errors. Find what's wrong with each failing request, fix it, and get the full chain passing end to end.

API & IntegrationsRoot Cause AnalysisTechnical Trade-offs
Author's notes

This was more involved than I expected.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Start by systematically inspecting each failing request's method, URL, headers, and body against the API documentation, then isolate and fix issues one at a time while verifying each fix with a test call. After all individual requests pass, run the full sequence end-to-end to catch any state or dependency issues.

Pro tip: Demonstrate production maturity by checking for idempotency and rate limiting early, and always capture the full error response body and headers—not just the status code—to pinpoint the root cause quickly.

1. Reproduce and capture details

Re-run each failing request individually and log the full HTTP response (status, headers, body) to understand the exact error messages and codes.

2. Validate request against API contract

Compare the request's method, URL, query params, headers (auth, content-type), and body schema with the API documentation to spot mismatches.

3. Fix and verify one request at a time

Apply the minimal correction for each issue (e.g., add missing auth header, correct JSON field) and re-run that single request to confirm it now returns 2xx.

4. Run the full chain end-to-end

Execute all five requests in order to ensure no state dependencies or side effects break the sequence, and that the entire flow passes.

5. Document root causes and preventive measures

Summarize what was wrong with each request and suggest improvements like better error handling, validation, or logging to avoid similar issues.

Key Points to Mention

  • HTTP status code semantics (e.g., 400 vs 401 vs 403 vs 404 vs 429 vs 500) and what each indicates
  • Authentication and authorization mechanisms (API keys, OAuth tokens, scopes)
  • Request payload validation: JSON schema, required fields, data types, and encoding
  • Rate limiting and idempotency: handling 429s with backoff and using idempotency keys for safe retries
  • State dependencies between requests: ensuring resources created in earlier calls exist before later calls reference them
  • Systematic debugging approach: isolate, fix, verify, then integrate

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