Apex Architecture

Design workflow

1. Clarify the business invariant and entry points.
2. Identify data ownership and object relationships.
3. Map synchronous vs asynchronous work.
4. Define security boundary.
5. Define transaction and rollback requirements.
6. Choose the smallest architecture that supports reuse and testing.
7. Identify governor-limit and data-volume risks.
8. Define tests and observability before implementation.

Layering guidance

Use layers only when they provide a concrete benefit.