Time-to-Live Token Manager With Renewal and a Heavy Concurrent Read/Write Follow-up
Company: Apple
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Technical Screen
Overview: Implement a token manager in which each token expires a fixed time-to-live after it is generated or renewed, renewals extend only unexpired tokens, and a query counts live tokens. The follow-up asks how to keep it correct and fast under heavy concurrent reads and writes.