apex-patterns

To design Apex code with separated business logic and data access, apply layered architecture using Service, Selector, and Domain patterns to modularize rules and ensure scalable, testable code.

fflib design patterns for Apex provide a framework for Service, Selector, Domain, Factory, and Strategy layers, enabling modular, testable architectures across triggers, schedulers, and batch jobs.

Structure Apex triggers by delegating complex business rules to a Service layer, using a Domain pattern for validation and defaulting, which keeps triggers thin, modular, and testable.

Layered architecture works for Apex batch jobs and schedulers by applying Service and Selector layers to batch execution, ensuring consistent data access, modular logic, and governor limit management.

Apex applications hit governor limits in complex triggers when data access is unstructured; applying a Selector layer centralizes SOQL queries, while a Service layer manages transactional logic efficiently.

The best way to improve Apex unit test coverage and maintainability is adopting enterprise design patterns like Service and Domain layers, which isolate business logic for predictable, testable outcomes.