Design interview academy

LLD, HLD, and behavioral interviews in one place.

Start directly from the section grid below.

OOP concepts, design principles, patterns, and problem writeups from the LLD content folder.

Theory and solved examples for races, locks, atomic updates, idempotency, and transactions.

Browse Java implementations, compare versions, inspect class layouts, and save workspace state.

System design problems written as interview docs with diagrams, trade-offs, and deep dives.

Build reusable STAR stories, map them to common behavioral questions, and prepare focused answers.