@amanaryan23: 𝗛𝗲𝗿𝗲 𝗶𝘀 𝘁𝗵𝗲 𝗰𝗼𝗺𝗽𝗹𝗲𝘁𝗲 𝗿𝗼𝗮𝗱𝗺𝗮𝗽 𝗜 𝗰𝗼𝗺𝗽𝗶𝗹𝗲𝗱 𝗮𝗳𝘁𝗲𝗿 𝗿𝗲𝘀𝗲𝗮𝗿𝗰𝗵𝗶𝗻𝗴 𝗵𝗼𝘄 𝗲𝗻�…

Here is the complete roadmap I compiled after researching how engineers at Google, Microsoft, Meta, Amazon, and Netflix actually build real systems:

Phase 1 - Foundations (Weeks 1-3)

→ Scalability: Vertical vs Horizontal- when each breaks

→ Load Balancing: L4 vs L7, Round Robin vs Weighted vs Least Connections

→ Caching: LRU, LFU, TTL, Cache Stampede, Hot Key problem

→ CDN: how Netflix delivers video without touching a server for 99% of requests

→ DNS: what actually happens when you type google[dot]com

Phase 2 - Data Layer (Weeks 4-6)

→ SQL vs NoSQL: when each breaks, why Discord moved MongoDB → Cassandra → ScyllaDB

→ Indexing, Sharding, Replication

→ CAP Theorem: why Meta chose eventual consistency for their social graph

→ Consistent Hashing: how Uber routes requests to the same server

Phase 3 - Async & Messaging (Weeks 7–8)

→ Message Queues: Kafka vs RabbitMQ - the real difference

→ Fan-out patterns: how Twitter handles a celebrity with 50M followers tweeting

→ Event-driven architecture

→ Dead letter queues, at-least-once vs exactly-once delivery

Phase 4 - Advanced (Weeks 9-12)

→ Rate Limiting: token bucket, leaky bucket, sliding window - how Uber does it

→ Distributed Consensus: Raft, Paxos

→ Microservices vs Monolith: when to split, when not to

→ Observability: logging, metrics, distributed tracing

Phase 5 - Real System Designs (Weeks 13- 16)

→ Design Twitter / Instagram feed

→ Design WhatsApp / Discord

→ Design Uber / OLA

→ Design Netflix / YouTube

→ Design Google Search / URL Shortener

→ Design a Payment System like Stripe/Razorpay

I have build this roadmap from official engineering blogs, mock interviews, and studying how engineers at the companies above actually build these systems.

I’m sharing it in 16 posts. One concept at a time. With real examples. No fluff.

Save this post. Come back to it. Follow me (@amanaryan23) for the full series - starting this week.