devspar

A personal developer toolkit and interview-prep hub built with Next.js. Includes browser-based CSV/PDF tools (/csv-tools, /pdf-tools), system-design and coding-question study guides with flashcards and search (/system-design, /coding-questions, /interview-prep, /nextjs, /nodejs, /reactjs, /javascript, /genai), and a GenAI playground. Built on Next.js, bootstrapped with create-next-app.

Getting Started

First, run the development server:

npm run dev
# or
yarn dev
# or
pnpm dev
# or
bun dev

Open http://localhost:3000 with your browser to see the result.

You can start editing the page by modifying app/page.tsx. The page auto-updates as you edit the file.

This project uses next/font to automatically optimize and load Geist, a new font family for Vercel.

Learn More

To learn more about Next.js, take a look at the following resources:

• Next.js Documentation - learn about Next.js features and API.
• Learn Next.js - an interactive Next.js tutorial.

You can check out the Next.js GitHub repository - your feedback and contributions are welcome!

Deploy on Vercel

The easiest way to deploy your Next.js app is to use the Vercel Platform from the creators of Next.js.

Check out our Next.js deployment documentation for more details.

Study guides

The interview-prep pages (/interview-prep, /nextjs, /genai, ...) each keep their questions in app/<guide>/content.json and load from a generated static file (public/study/<guide>.html) plus one engine shared by every guide (public/study/engine.js: search, flashcards, the phone menu, progress shared across guides), rendered in an iframe by app/components/StaticPrepClient.tsx.

After editing any content.json (by hand or with a script — see scripts/study/README.md for the toolkit and worked examples), regenerate the generated files:

npm run study:build

This runs automatically before npm run build, so a forgotten regeneration can't ship a stale site — but the generated public/study/*.html, public/study/engine.js, public/search-index.json and app/lib/studyMeta.json are committed like any other file, so commit them with the content change.

npm test (after npm run build) starts a production server and checks that every guide loads, the shared engine works, and the homepage's links and search work — see tests/.

/my-prep is an encrypted private page (scripts/encrypt-private.mjs); nothing links to it, and it is deliberately never part of public/study/ (its content only exists client-side, after the reader's own password decrypts it).

SEO

Set NEXT_PUBLIC_SITE_URL in the deploy environment (the production domain, e.g. https://devspar.example.com) — app/sitemap.ts and app/robots.ts use it to build absolute URLs, and fall back to http://localhost:3000 when it's unset, which is only correct for local development.