System Design

Reading the Problem

Learn to identify the real constraints: cost, latency, scale, before designing a solution.

Layers and Responsibilities

Separation of concerns: presentation, business logic, data access, and their interactions.

Data Modeling

SQL vs NoSQL, normalization, denormalization, relationships, and storage choices.

Monoliths vs Microservices

When to choose a monolith, when to switch to microservices, and how to orchestrate services.

Scalability

Horizontal vs vertical scaling, load balancing, replication, and sharding.

Caching Strategies

Distributed cache, client-side cache, invalidation, and caching patterns.

Message Queues

Synchronous and asynchronous queues, producer/consumer patterns, error handling and retries.

Observability

Monitoring, logging, tracing, and metrics to understand your system in production.

Tradeoffs and Decisions

CAP theorem, consistency vs availability, performance vs cost, and decision making.