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Abhishek Gupta
Abhishek Gupta

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System Design Expert

If your goal is to become a Senior Software Engineer, System Design Expert, or crack interviews at Google, Amazon, Microsoft, Meta, Uber, Netflix, then you should follow a structured roadmap.

The biggest mistake people make is directly jumping to "Design YouTube" or "Design WhatsApp."

Instead, System Design should be learned exactly like mathematics:

Learn Numbers → Addition → Multiplication → Algebra → Calculus

Similarly,

Learn Basics → Components → LLD → HLD → Distributed Systems → Real World Projects


🚀 Complete System Design Roadmap (0 → Monster)

                    SYSTEM DESIGN
                           │
        ┌──────────────────┴──────────────────┐
        │                                     │
      LLD                                 HLD
        │                                     │
        └──────────────┬──────────────────────┘
                       │
              Distributed Systems
                       │
              Real World Architectures
                       │
               Top Company Interviews
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📚 PHASE 0 — Prerequisites

Before learning System Design, you should know:

Programming

  • Variables
  • Functions
  • Loops
  • OOP
  • Exception Handling

Data Structures

  • Array
  • Linked List
  • Stack
  • Queue
  • Tree
  • Graph
  • Heap
  • HashMap

Algorithms

  • Sorting
  • Searching
  • BFS
  • DFS
  • Dynamic Programming (Basic)
  • Greedy

Database Basics

Learn:

  • SQL
  • NoSQL
  • Primary Key
  • Foreign Key
  • Index
  • Joins
  • Transactions

Networking Basics

  • HTTP
  • HTTPS
  • REST API
  • TCP
  • UDP
  • IP Address
  • Port
  • DNS

📖 PHASE 1 — System Design Fundamentals

This is the foundation.

Without this, nothing will make sense.


Chapter 1

Introduction to System Design

  • What is System Design
  • Why learn System Design
  • DSA vs System Design
  • Client Server Architecture
  • Real World Examples

Chapter 2

How Internet Works

Browser
   │
DNS
   │
Load Balancer
   │
Server
   │
Database
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Topics

  • Browser
  • Client
  • DNS
  • IP Address
  • Server
  • Database

Chapter 3

Scalability

Topics

  • Vertical Scaling
  • Horizontal Scaling
  • Peak Hours
  • Traffic
  • Resources

Chapter 4

Availability

Topics

  • Downtime
  • High Availability
  • Redundancy
  • Failover

Chapter 5

Single Point of Failure

Restaurant Example

One Chef ❌

One Server ❌

One Database ❌

Solutions

  • Backup
  • Replication
  • Multiple Servers

📖 PHASE 2 — Core Components

Now start learning the building blocks.


Load Balancer

Learn

  • Round Robin
  • Least Connection
  • Health Check
  • Reverse Proxy

Diagram

Users
   │
Load Balancer
   │
──────────────
│     │      │
S1    S2     S3
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Database

Learn

SQL

  • PostgreSQL
  • MySQL

NoSQL

  • MongoDB
  • Cassandra

Topics

  • Index
  • Transactions
  • Sharding
  • Replication

Cache

Topics

  • Redis
  • Memcached
  • Cache Aside
  • Write Through
  • Write Back
  • TTL

Diagram

User

↓

Server

↓

Redis

↓

Database
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Queue

Topics

  • RabbitMQ
  • Kafka
  • SQS

Learn

  • Producer
  • Consumer
  • Dead Letter Queue
  • Retry

CDN

Topics

  • Static Assets
  • Edge Server
  • Global Delivery

Storage

Learn

  • Object Storage
  • File Storage
  • Blob Storage

Example

Amazon S3


Search Engine

Topics

  • Elasticsearch
  • OpenSearch

API Gateway

Topics

  • Authentication
  • Rate Limiting
  • Routing

📖 PHASE 3 — Database Design

Topics

ER Diagram

Normalization

Denormalization

Indexes

Partitioning

Replication

CAP Theorem

ACID

BASE

Consistency

Availability

Partition Tolerance


📖 PHASE 4 — Low Level Design (LLD)

Now start object-oriented design.


OOP Revision

  • Class
  • Object
  • Encapsulation
  • Inheritance
  • Abstraction
  • Polymorphism

SOLID Principles

  • S
  • O
  • L
  • I
  • D

Design Principles

  • DRY
  • KISS
  • YAGNI

UML Diagrams

  • Class Diagram
  • Sequence Diagram
  • Activity Diagram
  • State Diagram

Design Patterns

Creational

  • Singleton
  • Factory
  • Builder
  • Prototype

Structural

  • Adapter
  • Facade
  • Decorator
  • Composite
  • Proxy

Behavioral

  • Strategy
  • Observer
  • Command
  • State
  • Iterator
  • Chain of Responsibility

LLD Problems

Design

  • Parking Lot
  • ATM
  • Library
  • Hotel
  • Cab Booking
  • Elevator
  • Snake Game
  • Chess
  • Cricbuzz
  • Splitwise
  • Vending Machine

📖 PHASE 5 — High Level Design (HLD)

Now architecture.

Topics


Scalability

Availability

Reliability

Maintainability

Fault Tolerance

Performance

Latency

Throughput

Consistency

Durability


Architecture

Monolith

Microservices

Serverless

Event Driven

Layered Architecture

Hexagonal Architecture

Clean Architecture


Communication

REST

GraphQL

gRPC

WebSocket

Message Queue


Deployment

Docker

Kubernetes

Nginx

CI/CD

Blue Green Deployment

Canary Deployment

Rolling Update


Observability

Logging

Monitoring

Tracing

Metrics

Alerting


Security

JWT

OAuth

Rate Limiting

API Gateway

Encryption

HTTPS

CORS

CSRF

XSS

SQL Injection


📖 PHASE 6 — Distributed Systems

This is where most interviews happen.

Topics


Replication

Master Slave

Leader Follower

Leader Election

Consensus

Paxos

Raft

ZooKeeper


Sharding

Horizontal Partitioning

Vertical Partitioning

Hash Based Sharding

Range Based Sharding


CAP Theorem

Consistency

Availability

Partition Tolerance


Distributed Cache

Redis Cluster


Distributed Lock

Redis Lock

ZooKeeper Lock


Event Driven Architecture

Producer

Consumer

Queue

Retry

DLQ


Streaming

Kafka

Pulsar

Event Streaming


📖 PHASE 7 — Cloud

AWS

Azure

Google Cloud


Learn

EC2

S3

Lambda

CloudFront

RDS

DynamoDB

EKS

ECS

IAM

VPC

CloudWatch


📖 PHASE 8 — DevOps

Git

GitHub

Docker

Docker Compose

Linux

Nginx

CI/CD

GitHub Actions

Terraform (Optional)


📖 PHASE 9 — Real World Architectures

Design these systems.

Easy

✅ URL Shortener

✅ Pastebin

✅ TinyURL


Medium

✅ Chat Application

✅ Food Delivery

✅ Cab Booking

✅ Hotel Booking

✅ Instagram Feed

✅ Notification Service


Advanced

✅ WhatsApp

✅ YouTube

✅ Netflix

✅ Google Drive

✅ Dropbox

✅ Uber

✅ Google Maps

✅ Twitter/X

✅ Facebook

✅ Discord

✅ Zoom


Monster

✅ Amazon

✅ Google Search

✅ Payment Gateway

✅ Banking System

✅ Kubernetes Control Plane


📖 PHASE 10 — Interview Preparation

Top interview questions.

Design

  • TinyURL
  • Instagram
  • YouTube
  • WhatsApp
  • Uber
  • BookMyShow
  • Paytm
  • Google Drive
  • Dropbox
  • Twitter
  • Notification System
  • Rate Limiter
  • API Gateway
  • Distributed Cache
  • Messaging Queue

📖 PHASE 11 — Become a Monster

Read production-level topics.

  • Event Sourcing
  • CQRS
  • Saga Pattern
  • Outbox Pattern
  • Idempotency
  • Circuit Breaker
  • Bulkhead Pattern
  • Service Mesh
  • Kubernetes
  • Multi Region Deployment
  • Disaster Recovery
  • Zero Downtime Deployment
  • Blue Green Deployment
  • Canary Deployment
  • Feature Flags

🎯 Complete Learning Path (Visual Roadmap)

                           SYSTEM DESIGN
                                  │
                     ┌────────────┴────────────┐
                     │                         │
              Fundamentals                 Networking
                     │                         │
                     └────────────┬────────────┘
                                  │
                          Core Components
                                  │
       ┌──────────────┬────────────┬─────────────┐
       │              │            │             │
   Database         Cache       Queue      Load Balancer
       │              │            │             │
       └──────────────┴────────────┴─────────────┘
                                  │
                           Database Design
                                  │
                           Low Level Design
                                  │
                          Design Patterns
                                  │
                          Object-Oriented Design
                                  │
                          High Level Design
                                  │
                        Distributed Systems
                                  │
                       Cloud + DevOps + Security
                                  │
                     Real World System Design
                                  │
                    FAANG Interview Preparation
                                  │
                           Senior Engineer
                                  │
                           Staff Engineer
                                  │
                        Software Architect
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📚 If You Want to Write the "World's Best System Design Notes"

I recommend organizing the notes into 30 sequential chapters, moving from beginner to advanced:

Chapter Topic
1 Introduction to System Design
2 How the Internet Works
3 Networking Fundamentals
4 Scalability
5 Load Balancers
6 Databases
7 Database Indexing & Query Optimization
8 Caching
9 Message Queues
10 Distributed Systems
11 CAP Theorem & Consistency
12 Storage Systems
13 API Design
14 Authentication & Authorization
15 Low-Level Design (LLD)
16 SOLID Principles
17 Design Patterns
18 UML & Object Modeling
19 High-Level Design (HLD)
20 Microservices
21 Event-Driven Architecture
22 Logging, Monitoring & Observability
23 Docker & Kubernetes
24 Cloud Architecture
25 Security in Distributed Systems
26 Reliability & Fault Tolerance
27 Performance Optimization
28 Real-World Case Studies (Netflix, WhatsApp, YouTube, Uber, etc.)
29 Top Product-Based Company Interview Questions
30 Complete System Design Interview Playbook & Revision Notes

This progression mirrors how experienced engineers learn: fundamentals first, then components, then design principles, followed by architecture, distributed systems, cloud, and finally real-world interview problems. It builds a strong foundation instead of memorizing solutions.

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