Glossary term
What is LRU (Least Recently Used)?
LRU stands for Least Recently Used.
A cache that removes the entry that was not used for the longest time. A hash map plus a doubly linked list makes it O(1).
Learn it properly · Practical Design ProblemsLesson 7: Design an LRU Cache, Idempotent Payments and Other Classic Mini-ProblemsShort worked designs: an LRU cache, idempotency keys, a job queue with retries and backoff, and feature flags.