Interview Prep Quizzes
Interactive quizzes designed for software engineers preparing for technical interviews. Every answer explains why, what the compiler produces, and what industry professionals do.
Primary keys, normalization, CAP theorem, sharding, CQRS, Event Sourcing, and distributed transaction patterns.
Event loop phases, garbage collection, streams, V8 internals, and CPU profiling.
B-Tree internals, composite indexes, covering indexes, and PostgreSQL index types.
CI/CD, Kubernetes, circuit breakers, Saga pattern, GitOps, and observability.
About interview prep on ToolNotch
ToolNotch interview prep is a collection of free, interactive quizzes for software engineers getting ready for a technical interview. Every quiz runs entirely in your browser: there is no account to create, nothing to install, and no paywall. You pick a topic, choose a difficulty level, and work through multiple-choice questions that mirror the kind of reasoning an interviewer is listening for.
What sets these quizzes apart from a flashcard deck is the explanation attached to every question. Instead of only telling you which option is correct, each answer explains why it is correct, shows the underlying mechanism, and adds a short note on how experienced teams apply the idea in production code. The goal is understanding you can defend under follow-up questions, not memorised trivia that collapses the moment an interviewer asks why.
The question banks are written from primary sources — official language handbooks, specification documents, and widely used engineering references — and are reviewed for accuracy rather than assembled from scraped quiz sites. Coverage currently centres on TypeScript, with further language and backend-engineering tracks released as they are finished.
How the quizzes are structured
Each track is split into Beginner, Intermediate, and Advanced levels of roughly ten questions each. Beginner questions confirm that the fundamentals are solid, Intermediate questions test the edge cases that trip people up in day-to-day work, and Advanced questions go after the deep behaviour that separates a senior candidate from a mid-level one. Question order is shuffled on every run, so you cannot pass by memorising positions.
Because everything is client-side, your answers and scores never leave your device. You can retake a level as many times as you want, jump straight to the difficulty you care about, and use the keyboard to move quickly: number keys to pick an option, Enter to advance, and Tab to cycle through the explanation tabs on questions that have them.
How to practise effectively
- Start one level below where you think you are. Clearing the Beginner set quickly confirms your fundamentals and builds momentum before you reach the harder material.
- Read the explanation on every question, including the ones you answered correctly. A right answer for the wrong reason is still a gap an interviewer can find.
- When an explanation mentions compiled output or a specification rule, pause and reproduce it yourself in an editor or REPL. Active recall beats re-reading.
- Retake a level a day or two later rather than immediately. Spacing the repetition is what moves an idea into long-term memory.
- Once you are consistently scoring above roughly 80% on Advanced, switch to explaining each answer out loud as if the interviewer were in the room. That is the skill the interview actually measures.
Interview prep FAQ
Are the ToolNotch interview quizzes free?
Yes. Every quiz is completely free with no account, sign-up, or download. All questions and explanations run client-side in your browser, and your scores are never uploaded anywhere.
Which topics are covered so far?
The TypeScript track is the most complete, with 30 questions across Beginner, Intermediate, and Advanced levels. Backend-engineering tracks — Node.js internals, database design and indexing, messaging systems, and system architecture — are being finished and released one at a time.
Are these questions aimed at junior or senior engineers?
Both. The Beginner level suits candidates preparing for their first or second role, while the Advanced level targets the depth expected of senior and staff engineers. Most people benefit from working through all three levels in order.
How should I use a quiz the day before an interview?
Do one relaxed pass at the level that matches the role, focus on reading the explanations rather than chasing a high score, and stop early enough to sleep. Cramming new material the night before tends to hurt more than it helps.
Do the quizzes save my progress?
Scores are shown at the end of each level but are not stored on a server. Because everything is local to your browser, you can retake any level as often as you like without affecting a saved record.