Why Learn System Design?
System design is the most important skill for senior software engineers and architects. Understanding how to build systems that handle millions of users, process terabytes of data, and remain highly available is crucial. This roadmap covers everything from basic concepts to advanced distributed systems patterns used at companies like Google, Amazon, and Netflix.
System Design Roadmap
- FundamentalsClient-server architecture, TCP/IP, HTTP/HTTPS, DNS, load balancers, and proxies.
- DatabasesSQL vs NoSQL, indexing, sharding, replication, CAP theorem, and ACID vs BASE.
- CachingRedis, Memcached, CDN, cache strategies (write-through, write-behind, cache-aside).
- Message QueuesKafka, RabbitMQ, SQS. Event-driven architecture, pub/sub patterns, and stream processing.
- Microservices ArchitectureService decomposition, API gateways, service discovery, inter-service communication.
- Distributed Systems ConceptsConsensus algorithms (Raft, Paxos), distributed transactions, Saga pattern.
- Scalability PatternsHorizontal vs vertical scaling, database sharding, read replicas, and eventual consistency.
- Real-World DesignDesign URL shortener, chat system, video streaming platform, ride-sharing app, and news feed.
Key System Design Skills
- Database Design — Schema design, indexing strategies, query optimization
- Caching Strategy — Multi-level caching, cache invalidation, CDN integration
- Load Balancing — Algorithms (round-robin, least connections), health checks
- API Design — REST, GraphQL, gRPC, versioning, rate limiting
- Reliability — Fault tolerance, redundancy, disaster recovery, SLAs/SLOs
Design Example: URL Shortener
Functional Requirements:
- Generate short URLs
- Redirect to original URL
- Track click analytics
Non-Functional:
- High availability
- Low latency redirects
- Handle millions of URLs
Components:
- Web server (load balanced)
- Redis cache (hot URLs)
- SQL database (persistent storage)
- Hash function (base62 encoding)
- Analytics service (event-driven)
Recommended Practice
- Design a URL shortener (bit.ly clone)
- Design a real-time chat application
- Design a video streaming platform (YouTube-style)