Study Notes by Niladri & AI

START-HERE

9 min read

🚀 START HERE - System Design Interview Quick Start

Welcome! This is your complete guide to preparing for system design interviews using Alex Xu’s books.

✅ Quick Setup (5 minutes)

  1. Open in Obsidian (if you’re using it)

    Open folder: /Users/niladri.roy/Learn/System Design/SDI-Notes

  2. Install Spaced Repetition Plugin (for flashcards)

    • Settings → Community plugins → Browse
    • Search “Spaced Repetition” → Install & Enable
    • Configure: Flashcard tags = #flashcards

  3. You’re ready! Start with the reading path below.

📚 First-Time Reading Path (Recommended Order)

Day 1: Foundations (1-2 hours)

  1. ✅ Read this file (you’re here!)
  2. 📖 Read interview-framework (30 min) - CRITICAL!
  3. 📖 Read estimation-cheatsheet (20 min) - Memorize key numbers
  4. 📖 Skim key-patterns (15 min) - Overview of patterns
  5. 📖 Skim distributed-system-components (20 min) - All building blocks

Day 2: Master the Framework (2 hours)

  1. 📖 Read ch03-framework-for-system-design (30 min)
  2. 🎴 Review flashcards vol1-ch03-framework (30 min)
  3. ✍️ Practice: Pick a simple system (URL shortener)
  4. ⏱️ Apply 4-step framework with 45-min timer

Day 3-4: Fundamentals (3-4 hours total)

  1. 📖 Read ch01-scale-from-zero-to-millions (45 min) ✅
  2. 📖 Read ch02-back-of-envelope-estimation (30 min) ✅
  3. 🎴 Review vol1-ch01-scaling (25 cards) ✅
  4. 🎴 Review vol1-ch02-estimation (25 cards) ✅
  5. ✍️ Practice calculations from estimation-cheatsheet

Day 5+: System Designs

All chapters are now available — pick based on target company or interest:

Volume 1 (Ch 4-15)

Volume 2 (All 13 chapters — now available)

See “Study Strategies” below for recommended paths.

🎯 Study Strategies

For Interview in 1 Week

Intensity: 3-4 hours/day

Day 1: Framework + Estimation (read + practice)
Day 2-3: Volume 1, Ch 4-7 (Rate limiter, Consistent hashing, Key-value store, ID generator)
Day 4-5: Volume 1, Ch 10-12 (Notification system, News feed, Chat system)
Day 6: Mock interview practice (2-3 designs, timed)
Day 7: Light review, rest, confidence building

Focus: Master the framework, practice articulating trade-offs, time management.

For Interview in 1 Month

Intensity: 1-2 hours/day

Week 1: Foundations (Framework + Estimation + Ch 1-3)
Week 2: Core systems (Ch 4-9: Rate limiter through Web crawler)
Week 3: User-facing systems (Ch 10-15: Notification through Google Drive)
Week 4: Advanced (Volume 2, pick 4-6 relevant chapters) + Mock interviews

Focus: Deep understanding, all patterns, confident with framework.

For Interview in 3 Months

Intensity: 30-60 min/day

Month 1: Volume 1 completely (1 chapter every 2 days)
Month 2: Volume 2 — all 13 chapters are now available (cover all, or pick based on target company domain)
Month 3: Review, practice, mock interviews

Focus: Mastery, ability to handle any system, strong fundamentals.

Note: All Volume 2 chapters are now available in this workspace. You can study them in any order — see the chapter list in the “Day 5+” section above, or check README for the full structure.

🏢 Company-Specific Recommendations

FAANG/Big Tech

Read: All of Volume 1, most of Volume 2
Focus: Scale, distributed systems, consistency models
Volume 2 Chapters: All (especially 4, 5, 9, 11, 13)

Startups

Read: Volume 1 (Ch 1-3, 4, 6, 8, 10)
Focus: MVP design, pragmatic choices, cost-aware
Volume 2: Optional, pick 2-3 based on domain

E-commerce

Read: Volume 1 (focus Ch 7, 10, 11, 15)
Volume 2: Ch 7 (Hotel reservation), Ch 11 (Payment), Ch 12 (Digital wallet)
Extra: Study consistency, transactions, inventory systems

Social Media

Read: Volume 1 (Ch 10-13: Notification, News feed, Chat, Autocomplete)
Volume 2: Ch 2 (Nearby friends), Ch 5 (Metrics)
Extra: Fan-out patterns, real-time systems

Fintech

Read: Volume 1 (Ch 4, 7: Rate limiter, ID generator)
Volume 2: Ch 11 (Payment), Ch 12 (Digital wallet), Ch 13 (Stock exchange)
Extra: Study ACID, idempotency, consistency

Rideshare/Maps

Read: Volume 1 (Ch 10, 12: Notification, Chat)
Volume 2: Ch 1 (Proximity), Ch 2 (Nearby friends), Ch 3 (Google Maps)
Extra: Geospatial indexing, real-time matching

Streaming/Media

Read: Volume 1 (Ch 14, 15: YouTube, Google Drive)
Volume 2: Ch 9 (S3 object storage)
Extra: CDN, video encoding, adaptive bitrate

📖 How to Read a Chapter

Step 1: First Read (20-30 min)

  • Understand the problem statement
  • Follow the 4-step framework application
  • Note key trade-offs

Step 2: Create Flashcards (10-15 min)

  • Extract 5-10 key concepts
  • Write in flashcards folder
  • Use format: Question ? Answer (no blank lines!)

Step 3: Practice Drawing (15-20 min)

  • Draw the system on paper
  • Practice explaining out loud
  • Time yourself (aim for 30-45 min total)

Step 4: Review Patterns (5 min)

  • What patterns from key-patterns were used?
  • When would you use different patterns?
  • Note in your own words

Total time per chapter: 60-90 minutes

🎴 Flashcard Workflow

Daily Review (15-20 min):

  1. Open Obsidian
  2. Cmd+P → “Spaced Repetition: Review flashcards”
  3. Review all due cards honestly

Rating Guide:

  • Again: Didn’t remember - see in < 1 min
  • Hard: Barely remembered - see tomorrow
  • Good: Remembered well - see in 2-3 days
  • Easy: Very easy - see in 5-7 days

Tips:

  • Be honest with ratings!
  • Don’t review when tired
  • 20-30 new cards per day max
  • Consistency > intensity

✍️ Practice Routine

Daily Practice (30 min):

Option 1: Solo Practice

  1. Pick a system from the book
  2. Set timer (45 min)
  3. Go through 4 steps on paper
  4. Review: Did I follow framework? What to improve?

Option 2: With Peer

  1. Take turns as interviewer/candidate
  2. Interviewer asks questions, gives hints
  3. 45-min session
  4. 15-min feedback (both ways)

Weekly Mock Interview (1 hour):

  • Full interview simulation
  • Record yourself (audio/video)
  • Review recording
  • Note improvements

Red flags to watch for:

  • Spending > 10 min on requirements
  • Not drawing diagrams
  • No back-of-envelope math
  • Silent periods > 30 seconds
  • Not discussing trade-offs

📊 Progress Tracking

Update chapter status:

  • ⬜ Not started
  • 🟨 Read, need more practice
  • 🟦 Can explain, need to practice drawing
  • 🟩 Interview ready

Example:

Volume 1 Progress:
- 🟩 ch03-framework-for-system-design
- 🟦 ch04-rate-limiter
- 🟨 ch05-consistent-hashing
- ⬜ ch06-key-value-store

🔗 Key Resources

In this repo:

External:

Related notes:

  • DDIA Notes: /Users/niladri.roy/Learn/System Design/DDIA-Notes
  • Use for deep theory, SDI for interview prep

⚡ Quick Interview Prep (2 hours before interview)

Don’t cram! But if you must review:

1 hour before:

During interview:

  • Have estimation-cheatsheet open in another window (quick reference only!)
  • Remember the 4 steps
  • Think out loud
  • Ask questions
  • Discuss trade-offs

🎓 Learning Path Summary

Start Here (You are here!)
    ↓
Read: interview-framework.md
    ↓
Read: estimation-cheatsheet.md
    ↓
Read: key-patterns.md (skim)
    ↓
Read: Volume 1, Chapter 3 (Framework)
    ↓
Review: Flashcards for Chapter 3
    ↓
Practice: Apply framework to URL shortener
    ↓
Continue: Volume 1, Chapters 1-2 (Fundamentals)
    ↓
Pick path based on timeline:
    - 1 week: Fast track (core systems only)
    - 1 month: Standard (Volume 1 + selected Vol 2)
    - 3 months: Comprehensive (Both volumes)
    ↓
Practice: Daily mock interviews
    ↓
You're ready! 🎉

❓ Common Questions

Q: Should I read DDIA first?
A: Not necessary. SDI is more practical for interviews. Read DDIA for deep understanding after you land the job!

Q: Do I need to memorize solutions?
A: No! Understand the framework and patterns. Interviewers can tell if you’re reciting vs thinking.

Q: What if I don’t know a technology mentioned?
A: It’s OK! Focus on concepts. Say “I haven’t used X, but based on Y, I’d approach it like…”.

Q: How many systems should I practice?
A: Minimum 10-15 for basic readiness. 20-25 for strong preparation. Focus on diverse types (storage, messaging, real-time, batch).

Q: Should I use specific technologies in answers?
A: Yes, but explain WHY. “Redis for caching because it’s fast in-memory store with TTL support” not just “Redis”.

Q: What if I run out of time?
A: Prioritize finishing all 4 steps at high level over perfecting one step. Show breadth first.

🚀 You’re Ready to Start!

Your next action:

  1. ✅ Mark this file as read
  2. 📖 Read interview-framework (30 minutes)
  3. 🎯 Set your goal (1 week? 1 month? 3 months?)
  4. 📅 Block study time in calendar
  5. 🎉 Start learning!

Remember:

  • Process > perfect solution
  • Communication > knowledge
  • Trade-offs > memorization
  • Practice > theory

Good luck! 🍀 You’ve got this! 💪

Questions? Review this file again or check obsidian-setup for more details.

Last Updated: 2026-04-13

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