Practice
Practice tracks for real engineering interviews
Curated, production-grade problems with reference solutions. Each track is built from a public source repository, so new questions appear here within minutes of being added there.
Practice tracks
Curated, production-grade problems with reference solutions. New questions appear here automatically when added to the source repositories.
System Design Live
Interview-style design questions: URL shorteners, news feeds, chat, ride sharing, video streaming. Capacity math, partial diagrams you complete, follow-up scenarios with answers.
Data Engineering Live
Real production scenarios: late Kafka events, schema drift, silent ETL bugs, SQL plan reading, cost incidents. Inspired by what actually breaks in production.
Roadmaps
Staged, ordered learning paths. Each stage ends with something you build, not a quiz.
System Design Roadmap Live
Foundations, storage, caching, messaging, scaling, distributed systems, and the interview craft. Six months, in order.
Data Engineering Roadmap Live
SQL, modeling, batch, streaming, storage, reliability, and the interview craft. Six months, in order.
Concept library
Short, scenario-driven answers to the questions that come up on every architecture review. A reference you can hit before an interview.
System Design Concepts Live
70 of the most common system design questions: caching, load balancers, consistency, queueing, plus AWS / GCP / Azure trade-offs. Filterable by section.
Tip: Each problem hides its solution by default. Try the problem first; the solution unlocks with one click and stays unlocked for your next visit.