Beyond your API

Interactive blog posts on computer science and web development by Biswajit Rath.

LRU Cache Explained: Design, Java Implementation, and the Mistakes That Trip Up Senior Engineers

Mar 09, 2026

A deep, practical walkthrough of how LRU caches actually work, how to build one correctly in Java with a HashMap and a doubly linked list, and the subtle mistakes that cause bugs in interviews and in production.

Stop Designing REST APIs Wrong: 10 Mistakes Developers Keep Making

Mar 09, 2026

A practical guide to the 10 REST API design mistakes that create confusion, break clients, and add technical debt, with clear fixes for each.

Cut Your LLM Token Bill in Half - How TOON Rewrites the Rules of JSON

Nov 02, 2025

Discover how TOON (Token-Oriented Object Notation) can reduce your LLM API costs by 30-60% through smarter data formatting designed specifically for AI applications.

How Big Tech Checks Username Availability in a Fraction of a Second

Aug 10, 2025

A deep technical yet approachable breakdown of how massive platforms check username availability instantly while ensuring accuracy at scale.

Encoding, Hashing, Encrypting: The Ultimate Guide to Securing Your Data

Aug 07, 2025

Understand the key differences between encoding, hashing, and encryption - including how they work, their use cases, and real-world examples.

Winning Against the Odds: My Unforgettable Smart India Hackathon Journey

Nov 26, 2024

A thrilling journey through the Smart India Hackathon - intense challenges, last-minute changes, and an unexpected yet unforgettable win!