System Design
System Design Basics Every Developer Should Know
Core system design concepts explained simply—no PhD required.
The Problem
Most developers write code but don’t understand the systems their code runs on. When asked about scaling, caching, or database choices, they struggle to articulate trade-offs.
The Insight
System design isn’t about memorizing patterns. It’s about understanding trade-offs:
The Three Questions
Every system design decision comes down to:
- Latency vs Throughput — How fast vs how much?
- Consistency vs Availability — Correct data vs always responsive?
- Simplicity vs Scalability — Easy to build vs handles growth?
Key Concepts to Master
- Caching: Store frequently accessed data closer to the user
- Load Balancing: Distribute traffic across multiple servers
- Database Sharding: Split data across multiple databases
- Message Queues: Decouple producers from consumers
Practical Takeaway
Start with the simplest solution that works. Add complexity only when metrics prove you need it.
Rule of thumb: If you can’t explain your system design on a whiteboard in 5 minutes, it’s probably too complex.
Most systems don’t need microservices. Most apps don’t need Kubernetes. Solve the problems you actually have.