How Growing Backend Apps Lose Control of Entity Logic — and What to Do About It

As backend applications scale, entities like 'Customer' accumulate responsibilities beyond simple data fields, including authorization, validation, lifecycle states, concurrency checks, and audit trails. This growth causes the entity's logic to scatter across controllers, services, repositories, and event handlers without a clear architectural owner. The article argues that this fragmentation — termed 'entity gravity' — becomes problematic when changing one entity rule requires touching many unrelated parts of the codebase. To address this, the author proposes introducing an explicit entity infrastructure boundary that centralizes common mechanics like optimistic concurrency, transactional outbox entries, and versioning. This approach separates the application's business decisions from the shared infrastructure concerns surrounding an entity, reducing coordination overhead as systems grow.