Browse everything in the app, no quiz, just reference. Look up a pattern before drilling it, or review a tradeoff cold.
All 25 patterns with templates and the problems that use them.
31 concepts and 10 canonical prompts.
Each scenario with the canonical answer and when the opposite is right.
Snippet + its time and space, with the reasoning written out.
Complexity classes, data-structure ops, canonical algorithms, everything in one cheat sheet.
Production idioms: exponential backoff, idempotency keys, bloom filters, leases…
STAR-style prompts with rubrics and red flags to study.
Concurrency, distributed systems, database internals, and networking: techniques, tradeoffs, and Big O.
Common bugs to recognize: N+1, races, SQL injection, XSS, with the fix explained.
Buggy code patterns and the canonical fix: off-by-ones, closures, type coercion.
REST conventions: resource modeling, idempotency, pagination, status codes.
Canonical query recipes: window functions, CTEs, NULL handling, anti-joins.
OWASP, auth, JWT, CSRF, secrets, the checklist every senior should know.
Parking lot, elevator, chess, canonical class breakdowns and key decisions.
Dijkstra, MST, KMP, Fenwick: when to use each, with complexity.
Chat, e-commerce, multi-tenant, schemas with indexes and sharding decisions.
SQL vs NoSQL, ACID/BASE/CAP, sharding, replication, deep dives to defend a choice.