*System Design used to scare me.* I remember preparing for my first few interviews — reading random blogs, watching hours of YouTube videos, and still feeling lost when someone asked me about CAP or caching strategies. 😓 That’s when I realized… System design isn’t about knowing everything. It’s about understanding the right things deeply. Over time, I figured out that 80% of system design interview questions come from just 20% of concepts. So, I created this guide: Focused. Structured. Real-world backed. Here’s what’s inside👇 ✅ 4-Step Roadmap (esp. if your interview is in 15 days) ✅ 15+ core concepts broken down in simple terms ✅ Basics → Advanced (CAP, Queues, Microservices, Caching, DBs, etc.) ✅ 50 System Design Q&A (with diagrams + examples) ✅ Ultimate Cheat Sheet for quick revisions _Use coupon code SD20 for 20% OFF (limited slots only)_ *Check out the Guide here:* https://topmate.io/rajat_gajbhiye/1446625?coupon_code=SD20