System Design Basics Every Builder Should Know

Users and scale

Start simple. Add complexity when metrics prove you need it.

Stateless services

Easier to scale horizontally. Session state belongs in a store designed for it.

Caches

Great for read-heavy workloads. Plan invalidation early; it is where bugs hide.

Data stores

Pick based on access patterns, not hype. SQL is still the default for good reasons.

Draw boxes

Sketch components before you debate tools. Shared understanding saves weeks.