Stripe system design interview

Round 5 of 7 · 13 questions reported

See the whole loop
Length
60 min
Format
Design discussion in a shared document
They grade
Idempotency and retries, strong consistency for money, append-only records, a clear public API
Heads-up
Prompts come from payments and developer platforms (ledgers, webhook delivery, idempotent APIs). Some senior loops leave this round out.

Questions Stripe asks in this round 13

  • Design a payments ledgerSystem designDesign the double-entry ledger behind a payments API: money movements must never be lost or applied twice.
    Last asked Aug 2026
  • Design a feature flag serviceSystem designLet teams turn features on for a percentage of users or specific accounts, with changes reaching every service within seconds and no per-request network call.
    Last asked Oct 2026
  • Design a metrics monitoring systemSystem designCollect metrics from every host and service, store them as time series, power dashboards over months of data, and alert when thresholds are crossed.
    Last asked Aug 2026
  • Design a superhero dispatch systemSystem designDesign a system that sends superheroes to incidents across a city. An incident is reported with its location; the system finds an available hero nearby, assigns them and tracks…
    Last asked May 2026
  • Design a payment fraud detection systemML designScore every card payment for fraud within tens of milliseconds, balancing blocked fraud against declined good customers, with labels that arrive weeks later.
    Last asked May 2026
  • Design a webhook delivery systemSystem designDeliver event notifications to customers' HTTP endpoints at least once, with retries and backoff, signing, ordering where it matters, and isolation from slow endpoints.
    Last asked Dec 2025
  • Design an account takeover detection systemML designSpot logins and account changes made by someone other than the owner, scoring each event in real time and choosing to allow, challenge or block.
    Last asked Oct 2025
  • Design a distributed job schedulerSystem designDesign a service that runs millions of scheduled and on-demand jobs (cron-like and one-off) reliably across a fleet of workers.
  • Design a merchant lending systemSystem designOffer business loans to merchants based on their payment history, then repay automatically by withholding a share of each day's sales.
  • Design a payment systemSystem designAccept card payments for merchants: authorize, capture, settle with card networks, and reconcile, never charging twice or losing money.
  • Design a rate limiterSystem designDesign a service that limits how many requests each API client can make. It sits in front of every API endpoint at high traffic.
  • Design an access management systemSystem designDecide who can do what to which resource across many services: roles, groups, fine-grained permissions, fast checks on every request, and auditable changes.