Get ready for your
tech interview by actually practicing.
195+ questions, exercises and mock interviews for JavaScript, React, Node and Git. For juniors landing their first job — and for learning to explain out loud.
Flashcards
Cover the answer, say it out loud and grade yourself. Spaced repetition brings back what you forget most.
What does it print?
Predict the code output and run it in a browser sandbox to check if you were right.
Voice mock
Timed mock interview: the interviewer reads the questions and you answer out loud.
Boilerplates I use in my own projects, ready for you to start yours. Clone them or hit "Use this template" on GitHub.
next-structure
Production-ready Next.js 15 boilerplate: App Router, modular architecture (shared / modules), TanStack Query, Zustand, Zod, Tailwind v4, Husky with Conventional Commits and full TypeScript tooling.
Next.js 15 · React 19 · TypeScript · Turbopack · Tailwind v4 · TanStack Query · Zustand · Zod · React Hook Form · Jest
nest-structure
NestJS API with hexagonal architecture: JWT auth (access + refresh) with bcrypt, Drizzle ORM on PostgreSQL, local or S3 storage, React Email templates, Swagger at /api/docs and one-command module scaffolding.
NestJS 10 · TypeScript · Drizzle ORM · PostgreSQL · JWT · S3 · React Email · Swagger
react-structure
React 19 boilerplate with Vite, modular structure (shared / modules), React Router, TanStack Query, Zustand, Tailwind v4, ESLint + Prettier and Husky. Same architecture as next-structure, but as a pure SPA.
React 19 · Vite 7 · TypeScript · Tailwind v4 · React Router v7 · TanStack Query · Zustand · Jest
postgres-image
Ready-to-use PostgreSQL 16 (Alpine) Docker image, with docker compose and example credentials (admin / admin123, mi_base database). Perfect for spinning up a local development database in seconds.
PostgreSQL 16 · Alpine · Docker · Docker Compose
Learn, practice and explain out loud
It is not just reading answers: the site makes you produce — predict outputs, recall from memory and answer by speaking, which is exactly what happens in a real interview.
Pick a technology
JavaScript, React & TypeScript, Node & Express or Git. Each syllabus is organized by topic, from fundamentals to advanced.
Practice in 3 modes
Spaced-repetition flashcards, "what does it print?" exercises you run in the browser, and voice mock interviews.
Explain it out loud
Interviews are won by explaining. Mock interviews read the question to you and you answer by speaking, just like real life.
Built for junior developers
Everything in English and Spanish
Practice in your language or get ready for interviews in English. Switch languages anytime.
Run real code
Output exercises run in a safe browser sandbox. No guessing — you verify.
Your progress is yours
Spaced repetition saves your progress in your browser. No accounts, no tracking, no cost.
100% free and open
A community resource for the community. No paywalls, no limits.
Ready to practice?
Pick your technology and start now. It is free and you do not need an account.
See the syllabus