SDE Interview Preparation Guide with Deepak Bhagtani

📘 The Complete SDE Interview Preparation Guide (2026 Edition)

Everything you need to crack SDE/SWE interviews at product-based companies - in one document.

Stop hunting across 15 different YouTube playlists, GitHub repos, and half-finished notion docs. This is a single, structured, 60+ page guide that takes you from "where do I even start" to "walking into my onsite loop with a plan" - covering DSA, CS fundamentals, System Design, Low-Level Design, and Behavioural rounds, all in one place.

Built for freshers, career switchers, and working engineers targeting Big Tech, unicorns, and high-growth product companies.

🎯 Who this is for

You have an interview coming up (or are actively applying) and want a single source of truth to prep from

You're overwhelmed by scattered resources and want a clear roadmap instead

You know some DSA but freeze on system design, LLD, or behavioral rounds

You want templates and frameworks, not just 500 random problems with no structure

📖 What's inside (12 parts, fully structured)

1. Understanding the Game - How hiring actually works: OA → phone screen → onsite loop, what changes by level (SDE-1/2/3), and exactly what interviewers are scoring you on.

2. Preparation Roadmap - Ready-made 4-week, 8-week, and 12-week study plans depending on how much time you have, plus a mistake-journal system for spaced repetition.

3. Foundations - Big-O from first principles, and the single most useful trick in DSA: reading problem constraints to instantly know the intended time complexity.

4. Data Structures & Algorithms (the core) - Every major pattern (two pointers, sliding window, binary search, backtracking, graphs, DP, greedy, tries, heaps, and more) explained with working code templates, a pattern-recognition cheat sheet, and curated practice problems for each.

5. CS Fundamentals - OS (processes, deadlocks, scheduling), DBMS (ACID, indexing, normalization, SQL with real interview queries), Networking (TCP/UDP, HTTPS, "what happens when you type a URL"), and OOP/SOLID - the stuff that trips people up in fundamentals rounds.

6. Low-Level Design (LLD) - SOLID principles, must-know design patterns (Strategy, Observer, Factory, etc.), a repeatable approach to any machine-coding round, and a fully worked Parking Lot example with code.

7. High-Level Design (System Design) - The complete framework (requirements → estimation → API → data model → architecture → deep dive), all the core building blocks (caching, sharding, load balancing, queues, consistent hashing, CAP theorem), a worked URL-shortener example, and a cheat sheet covering 15+ classic case studies (Twitter, Uber, WhatsApp, rate limiters, and more).

8. Behavioural & Leadership Interviews - The STAR method done right, how to build a reusable story bank, and the most commonly asked behavioural questions.

9. How to Perform in the Room - Live interview tactics: how to think out loud, what to do when you're stuck, how to test your own code, and how to handle nerves.

10. Resume, Online Assessments, Referrals & Offers - Resume bullet formulas that actually get shortlisted, Online Assessments strategy, how to get referrals, and how to negotiate an offer.

11. Curated Problem Lists & Resources - A minimal high-yield list of ~60 must-do problems organised by pattern, plus trusted books and platforms.

12. Final Checklists - A complete readiness checklist, the most common mistakes candidates make, and a printable 12-week progress tracker.

✅ Why this guide is different

Not just a problem list - every topic explains the why, not just the what

Code templates you can actually memorise - clean, minimal, interview-ready

One document, one system - no more jumping between 10 tabs

Structured for self-study - clear roadmap, checklists, and progress tracker included

📦 What you get

60+ page premium PDF (print-ready, clean formatting, clickable table of contents)

Lifetime access to your copy

Practical, no-fluff content - just what you need to prepare with confidence

💡 A note

This guide won't magically get you an offer - but it will save you weeks of figuring out what to study and how to structure your prep, so you can spend that time actually practicing.