Reason About Rate Limiting Under Memory and Throughput Pressure
Company: Plaid
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Onsite
Overview: Design an in-memory rate limiter that remains useful when request volume makes per-request queues too costly. Compare exact and approximate policies while addressing configurable boundaries, bucketed memory, concurrency, sharding, hot keys, throughput, and explicit precision or overshoot tradeoffs.