System Design Learning Guide¶

Introduction¶

This folder contains materials for systematically learning System Design. You can learn step-by-step from core concepts to practical patterns needed to design large-scale systems. It helps with technical interview preparation and improving practical architecture design skills.

Target Audience: Backend developers, system architects, technical interview candidates

Learning Roadmap¶

[Basics]                  [Intermediate]            [Advanced]
  │                         │                         │
  ▼                         ▼                         ▼
System Design Overview ──▶ Load Balancing ─────▶ Distributed Cache
  │                         │                         │
  ▼                         ▼                         ▼
Scalability Basics ─────▶ Reverse Proxy ─────▶ Database Scaling
  │                         │                         │
  ▼                         ▼                         ▼
Network Review ──────────▶ Caching Strategy ───▶ Database Replication
  │                         │                         │
  ▼                         ▼                         ▼
                      API Gateway ─────────▶ Message Queue
                                                 │
                                                 ▼
                                            Microservices
                                                 │
                                                 ▼
                                            Distributed Systems
                                                 │
                                                 ▼
                                            Practical Design

Prerequisites¶

Required
Networking basics (HTTP, DNS, TCP/IP) → Networking/
Database basics (SQL, transactions) → PostgreSQL/
At least 1 programming language
Recommended
Linux basic commands → Linux/
Docker basics → Docker/
REST API concepts → Web_Development/

File List¶

Basics (01-03)¶

Filename	Difficulty	Key Topics
01_System_Design_Overview.md	⭐	What is system design, interview criteria, problem approach framework
02_Scalability_Basics.md	⭐⭐	Vertical/horizontal scaling, CAP theorem, PACELC
03_Network_Fundamentals_Review.md	⭐⭐	DNS, CDN, HTTP/2/3, REST vs gRPC

Load Balancing and Proxy (04-05)¶

Filename	Difficulty	Key Topics
04_Load_Balancing.md	⭐⭐⭐	L4/L7 load balancers, distribution algorithms, health checks
05_Reverse_Proxy_API_Gateway.md	⭐⭐⭐	Reverse proxy, API Gateway, Rate Limiting

Caching (06-07)¶

Filename	Difficulty	Key Topics
06_Caching_Strategies.md	⭐⭐⭐	Cache-Aside, Write-Through, cache invalidation
07_Distributed_Cache_Systems.md	⭐⭐⭐	Redis, Memcached, consistent hashing

Database Scaling (08-10)¶

Filename	Difficulty	Key Topics
08_Database_Scaling.md	⭐⭐⭐	Partitioning, sharding strategies, rebalancing
09_Database_Replication.md	⭐⭐⭐	Leader replication, Quorum, failure recovery
10_Data_Consistency_Patterns.md	⭐⭐⭐	Consistency models, eventual consistency, strong consistency

Message Queue (11-12)¶

Filename	Difficulty	Key Topics
11_Message_Queue_Basics.md	⭐⭐⭐	Async processing, Kafka, RabbitMQ
12_Message_System_Comparison.md	⭐⭐⭐⭐	Kafka vs RabbitMQ, use cases

Microservices (13-14)¶

Filename	Difficulty	Key Topics
13_Microservices_Basics.md	⭐⭐⭐⭐	Monolith vs MSA, service decomposition
14_Microservices_Patterns.md	⭐⭐⭐⭐	Service mesh, Circuit Breaker, Saga

Distributed Systems (15-16)¶

Filename	Difficulty	Key Topics
15_Distributed_Systems_Concepts.md	⭐⭐⭐⭐	Distributed system properties, failure models
16_Consensus_Algorithms.md	⭐⭐⭐⭐⭐	Raft, Paxos, leader election

Practical Design (17-18)¶

Filename	Difficulty	Key Topics
17_Design_Example_1.md	⭐⭐⭐	URL shortener, Pastebin design
18_Design_Example_2.md	⭐⭐⭐⭐	Chat system, notification system design

Observability and Search (19-20)¶

Filename	Difficulty	Key Topics
19_Observability_Monitoring.md	⭐⭐⭐⭐	Three pillars, Prometheus, ELK, OpenTelemetry, SLO/SLI
20_Search_Systems.md	⭐⭐⭐⭐	Elasticsearch, inverted index, BM25, scaling search

Recommended Learning Path¶

Phase 1: Build Foundations (1 week)¶

01_System_Design_Overview → 02_Scalability_Basics → 03_Network_Fundamentals_Review

Learn core concepts and interview approach to system design.

Phase 2: Traffic Handling (1 week)¶

04_Load_Balancing → 05_Reverse_Proxy_API_Gateway

Learn traffic distribution and API management.

Phase 3: Master Caching (1 week)¶

06_Caching_Strategies → 07_Distributed_Cache_Systems

Deep dive into caching, core to performance optimization.

Phase 4: Database Scaling (1-2 weeks)¶

08_Database_Scaling → 09_Database_Replication → 10_Data_Consistency_Patterns

Learn DB scaling strategies for large-scale data.

Phase 5: Message Queues and Microservices (2 weeks)¶

11_Message_Queue_Basics → 12_Message_System_Comparison → 13_Microservices_Basics → 14_Microservices_Patterns

Learn async processing and distributed architecture patterns.

Phase 6: Distributed Systems and Practical Design (2-3 weeks)¶

15_Distributed_Systems_Concepts → 16_Consensus_Algorithms → 17_Design_Example_1 → 18_Design_Example_2

Cover distributed systems theory and practical design problems.

Phase 7: Observability and Search (1-2 weeks)¶

19_Observability_Monitoring → 20_Search_Systems

Learn system monitoring, alerting, and search system design.

Interview Preparation Tips¶

System Design Interview Approach¶

┌─────────────────────────────────────────────────────────────────┐
│                System Design Interview 4 Steps                   │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│  1. Clarify Requirements (5 min)                                │
│     ┌────────────────────────────────────────────────────────┐  │
│     │ • Confirm functional requirements                      │  │
│     │ • Non-functional requirements (performance, etc.)      │  │
│     │ • Scale estimation (users, traffic)                    │  │
│     └────────────────────────────────────────────────────────┘  │
│                                                                  │
│  2. Back-of-the-envelope Calculation (5 min)                    │
│     ┌────────────────────────────────────────────────────────┐  │
│     │ • QPS (Queries Per Second)                             │  │
│     │ • Storage capacity                                     │  │
│     │ • Bandwidth                                            │  │
│     └────────────────────────────────────────────────────────┘  │
│                                                                  │
│  3. High-Level Design (15-20 min)                               │
│     ┌────────────────────────────────────────────────────────┐  │
│     │ • Main component diagram                               │  │
│     │ • Data flow                                            │  │
│     │ • API design                                           │  │
│     └────────────────────────────────────────────────────────┘  │
│                                                                  │
│  4. Detailed Design (15-20 min)                                 │
│     ┌────────────────────────────────────────────────────────┐  │
│     │ • Database schema                                      │  │
│     │ • Scaling strategy                                     │  │
│     │ • Trade-offs discussion                                │  │
│     └────────────────────────────────────────────────────────┘  │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

Frequently Asked Topics¶

Topic	Key Concepts	Related Files
URL Shortener	Hash function, Base62	08, 07
Chat System	WebSocket, message queue	03, 11
News Feed	Fan-out, caching	06, 07
Search Engine	Inverted index, sharding	08
Notification System	Message queue, priority	11, 12
File Storage	Distributed storage, chunks	08, 09

Interview Checklist¶

[ ] Did you clarify requirements?
[ ] Did you estimate scale?
[ ] Did you draw high-level architecture?
[ ] Did you design data model?
[ ] Did you identify bottlenecks?
[ ] Did you propose scaling strategy?
[ ] Did you discuss trade-offs?

Links to Other Folders¶

Folder	Related Content
Networking/	DNS, HTTP, TCP/IP, network security
PostgreSQL/	Database, transactions, replication
Docker/	Containerization, microservices deployment
Linux/	Server management, performance monitoring

Recommended Books¶

Designing Data-Intensive Applications - Martin Kleppmann
System Design Interview - Alex Xu
Building Microservices - Sam Newman
Web Scalability for Startup Engineers - Artur Ejsmont

Online Resources¶

Learning Tips¶

Draw Diagrams: Draw system architectures yourself
Number Sense: Get familiar with QPS and storage capacity calculations
Trade-offs: Every decision has pros and cons
Real Examples: Analyze architectures of large services
Interview Practice: Practice explaining out loud

Document Information - Last Updated: January 2026 - Total Study Time: Approximately 6-8 weeks