03
Core Knowledge
The fundamentals interviewers assume you have — concepts, SQL, security, concurrency, and design.
0 done— accuracy
Concepts
Recall-style: think first, then reveal. No multiple choice.
110 questions
Flashcards
Pattern definitions and when to use them, self-rated.
22 patterns
Systems & Concurrency
Concurrency, distributed, database, networking scenarios.
44 scenarios
SQL
Schema plus question — JOINs, windows, NULL traps.
15 drills
Security
OWASP, auth, JWT, CSRF — what seniors are assumed to know.
15 questions
OOP Design
Parking lot, elevator, chess. Design the classes, compare.
10 prompts
Shuffle all 6 modes
$ drill core-knowledge --random