Advanced JavaScript Interview Handbook

Most JavaScript interview resources stop at theory.

This handbook goes deeper.

Built specifically for frontend rounds at product companies.

What's inside:

1. Array Polyfills - map, filter, reduce, etc.
2. Function Polyfills - call, apply, bind
3. Utility Polyfills - debounce, throttle, curry, etc.
4. Promise Polyfills - Promise.all, Promise.allSettled
5. Data Structures & Patterns - EventEmitter, LRU Cache, groupBy
6. Advanced Browser APIs - Proxy, Reflect, Atomics, etc
7. Security -, CSRF, Security Headers, Content Security Policy
8. Memory & Performance - Garbage Collection, Memory Leaks
9. Code Snippets — Output questions and bug fixes on closures, promises, async loops, hoisting, prototype chain and more

Every topic includes:

1. Clear explanation
2. Real code example
3. Follow-up interview question asked on it
4. Common mistake candidates make

Who this is for:

1. Frontend engineers preparing for product company interviews
2. Anyone who clears theory rounds but struggles with implementation questions
3. Developers who want to go beyond surface-level JavaScript