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1. 01 Explain `localStorage` — its capacity, synchronous nature, and same-origin scoping. Easy
2. 02 Why should you avoid storing sensitive data like JWTs in `localStorage`? Explain the XSS risk. Medium
3. 03 How would you build a typed wrapper around `localStorage` that handles JSON serialization and quota errors safely? Medium
4. 04 Explain the `storage` event — how can you sync state across multiple browser tabs using `localStorage`? Hard
5. 05 What happens when `localStorage.setItem` exceeds the quota? How should you handle `QuotaExceededError`? Medium
6. 06 Explain how `sessionStorage` differs from `localStorage` in lifetime and scope (per-tab vs per-origin). Easy
7. 07 Does `sessionStorage` persist across a page refresh? Across opening a new tab to the same URL? Explain why. Medium
8. 08 Give a real use case where `sessionStorage` is preferable to `localStorage` (e.g., a multi-step form wizard). Easy
9. 09 How would you persist and restore scroll position per-tab using `sessionStorage`? Medium
10. 10 Explain `HttpOnly`, `Secure`, and `SameSite` cookie attributes and what security threats each mitigates. Medium
11. 11 Compare cookies, localStorage, and sessionStorage in terms of size limits, expiry, and being sent with HTTP requests. Medium
12. 12 Why can JavaScript not read an `HttpOnly` cookie, and why is that a deliberate security feature against XSS? Medium
13. 13 Explain `SameSite=Strict` vs `Lax` vs `None` and their role in CSRF mitigation. Hard
14. 14 Implement a small utility to get, set, and delete a cookie using `document.cookie`. Easy
15. 15 What is IndexedDB and when would you choose it over localStorage for a frontend application? Medium
16. 16 Explain object stores, indexes, and transactions in IndexedDB. Hard
17. 17 Why is the native IndexedDB API callback/event-based, and how do libraries like `idb` wrap it in Promises? Medium
18. 18 Design an offline-first data layer for a note-taking app using IndexedDB with background sync to a server. Hard
19. 19 Explain versioning in IndexedDB (`onupgradeneeded`) and how schema migrations are handled. Hard