Become the engineer companies are actually hiring for.
Five levels per track — read the chapter, answer the scenarios, unlock the next. AI engineering is our headline track; the others reinforce the system-design muscle behind it.
AI Engineering Featured
Foundations → LLM engineering → RAG → agents → production. 23 chapters, 100 scenarios.
High-Level Design
Distributed systems, scaling, replication, sharding. 17 chapters, 111 scenarios.
Low-Level Design
SOLID, design patterns, 15 worked LLD problems. 21 chapters, 100 scenarios.
DS & Algorithms
Pattern-driven prep — arrays, trees, graphs, DP. 100 scenarios.
From millions to billions.
Real architecture decisions from the products you use every day — Discord, Stripe, WhatsApp, Uber, Netflix, Pinterest, Figma, and more. The constraint that forced the rewrite. The boring tech that won. The cleverness you can steal.
Don't lose the offer in the behavioural round.
Six skills senior+ rounds actually test, the 60-minute structure, STAR done right, 18 real questions, a week-long prep drill, and the reverse-interview questions that signal "senior" to a hiring manager.