How to Build an LRU Cache from Scratch in JavaScript

· Anton Liberant · March 6, 2026, 3:41 a.m.
Summary
This blog post provides a step-by-step guide to building a Least Recently Used (LRU) cache from scratch in JavaScript. It utilizes a Map and doubly linked list to achieve O(1) operation complexity, along with clear explanations and code examples.
AUTHOR
Sponsored
Zulip logo Zulip
Organized team chat for people who take work seriously. Topic-based threading keeps conversations focused.
Try Zulip
Become a sponsor →