Clean Architecture

Clean Architecture organises code in concentric rings: entities and use cases in the centre, interfaces and frameworks at the edge. Dependencies point inward, keeping business rules independent of delivery and databases.

When it fits

• Complex domains where business rules outlive frameworks
• Long-lived systems that will change infrastructure over time

Risks

• More layers and abstractions than simple apps need

Real-world examples

• Enterprise systems that survive multiple UI rewrites and database migrations with minimal change to core use cases
• SaaS products that share a core domain across CLI, API and web UI adapters

Practical tips

• Keep use cases pure and side effect free; push I/O to boundaries
• Make dependencies flow inward via interfaces, not concrete types