- Is this full-stack interview prep really free?
- Yes. The entire curriculum, including over 200+ Data Structures & Algorithms questions, system design guides, and React/Node.js cheat sheets, is 100% open-source and free forever.
- Which companies are these questions meant for?
- Our curriculum is meticulously categorized into FAANG (Google, Amazon, Meta, Microsoft, Oracle) and top Service companies (TCS, Infosys, Wipro, Accenture). We track the exact questions asked in their most recent 2026 hiring cycles.
- Do I need to know both React and NestJS?
- While the book heavily features React on the frontend and Node.js/NestJS on the backend, the core architectural concepts (System Design, Microservices, Authentication, Database Indexing) apply universally across any technology stack.
- What are the career roadmaps?
- Stage-by-stage study maps for the roles hiring right now — 50 tracks covering 1233 topics, from AI and ML engineering to data, MLOps, and forward deployed engineering. Each one tells you what to learn, in what order, and what to build to prove it.
- Do I need an account, and how is my progress saved?
- There is no account and no sign-up. Ticked topics and roadmap progress are stored in your own browser using localStorage, so nothing is uploaded and nothing is tracked. Clearing your browser data resets your progress, and it does not follow you to another device.
- Can I run the code examples?
- Yes. The JavaScript Playground runs your code directly in your browser inside a sandboxed frame — no server, no account, and your code never leaves your machine. Use it to tweak any example from the book and see the console output immediately.
- How do I report an error or contribute?
- The whole book is a public GitHub repository. Open an issue for anything that looks wrong or out of date, or send a pull request — corrections, new questions, and better explanations are all welcome.