plaid interviews focus on API design: 1. design a bank account linking API from scratch. handle OAuth flows, token management, error states 2. coding: implement webhook delivery with retry logic, idempotency, and dead letter queue 3. system design: design a transaction categorization pipeline that processes 50M transactions/day 4. security deep dive: how would you handle PII in a financial data pipeline? the security round was unique. most companies dont test security knowledge explicitly

Plaid senior backend - fintech API design

plaid interviews focus on API design: 1.

the webhook retry + idempotency + DLQ problem is a fantastic interview question. tests distributed systems knowledge in a very practical way

security round at plaid is no joke. they handle bank credentials for millions of users