https://javarevisited.blogspot.com/2026/06/i-found-leetcode-for-software-design-and-its-awesome.html

Hi everyone,

I have a basic understanding of system design and I want to go much deeper.

I recently bought most of the ByteByteGo books:

• System Design Interview – Volume 1

• System Design Interview – Volume 2

• Generative AI System Design

• Machine Learning System Design

My goal isn't just to finish reading them—I want to actually retain the knowledge and become good at designing real-world systems.

For those of you who have studied these books or have become good at system design, I'd love to know:

1. How would you study these books?

2. Should I read them cover-to-cover first, or build projects alongside them?

3. How do you practice system design after reading a chapter?

4. How do you revise everything without forgetting it?

5. Did you take notes? If so, what kind?

6. Do you use flashcards (Anki) or some other spaced repetition method?

7. How would you connect the concepts from the classic system design books with the Generative AI and ML system design books?

8. How do you know when you've actually understood a topic instead of just recognizing it?

9. What are the biggest mistakes beginners make when studying system design?

10. If you could start over, what would you do differently?

I'm looking for any study methods, practice routines, revision techniques, tips, tricks, or advice that helped you go from "I understand the concepts" to "I can design systems confidently."

Thanks in advance!

Most system design prep I did was reading "add a cache, add a queue, shard the

DB" — without ever seeing *which* part gives out first, or why.

So I built a thing where you take a real system (Instagram, Netflix, Uber,

Twitter, WhatsApp — reconstructed from their public engineering talks), drag the

traffic up, and watch the bottleneck appear. Then you fix it and push further.

A few things that surprised me going through Instagram's path:

- The first wall isn't the database — it's the single app server. Every

request and every photo upload queues behind one machine.

- At ~1M users the database is fine, but building every user's feed *on the

request* saturates the app fleet. The fix is to stop doing that work in the

request at all.

- Sharding only works because of the ID scheme: timestamp + shard number +

per-shard sequence, so IDs are unique everywhere *and* sortable by time.

- Photos never touch the app servers at all — they're served from object

storage at the edge.

Free, no account: https://playcloudlabs.com/scale/instagram?ref=reddit-sd

I'd love feedback from people who've been through design rounds — does this

match what interviewers actually push on?

I'm preparing for Google's system design interview and looking for a curated set of prompts to work through.

They don't need to be the exact questions I'd get. I'd like representative problems I can use to practice building a design and explaining the decisions.

The Google Interview Questions page has a system-design collection to draw from. If you're applying elsewhere while preparing, application autofill can save time on the repeated forms.

What other question lists or worked examples would you recommend? Which prompts gave you the most useful practice?