writing-solid-rust

Apply hexagonal architecture in Rust by defining domain-focused traits as ports and implementing infrastructure-specific adapters. This separates business logic from external concerns, creating a modular system with plug-in backends and testable domain logic independent of infrastructure frameworks.

Structure a Rust application using SOLID principles by defining independent domain types and trait-based ports for dependencies. Implement adapters that map infrastructure errors to domain errors, ensuring the domain remains isolated, testable, and compliant with SRP, ISP, OCP, and DIP.

Yes, you can build modular Rust systems with plug-in adapters by defining ports as traits in the domain layer. Adapters implementing these ports can be swapped at the composition root, supporting backend services, UI components, and AI inference integrations without modifying core domain logic.

Test domain logic independently in hexagonal Rust by defining ports as traits and mocking or stubbing adapter implementations at the composition root. This allows unit testing the domain layer without relying on actual database, API, or infrastructure dependencies.

Hexagonal architecture works for Rust applications processing LLM inferences and payments by treating these external services as adapters behind domain-defined ports. This isolates domain logic from API changes, enabling testable and maintainable processing logic across different integration points.

Avoid hexagonal architecture and SOLID principles in small Rust projects where the overhead of defining ports, adapters, and independent domain types exceeds the complexity of the domain logic itself. For simple scripts or prototypes, direct implementation is more efficient than enforcing strict separation.