Anti Corruption Layer

A translation layer between two bounded contexts that protects your domain model from another context's concepts and changes.

An anti-corruption layer is a piece of code that translates between two bounded contexts so neither one has to speak the other's language. It lives at the edge of your context, usually inside an adapter, and converts external types into your domain types (and the other way around).

You reach for an ACL when you talk to a system you don't fully control. It might be a third-party API, a legacy service, or another team's bounded context with different naming and modeling choices. Without an ACL, those external concepts leak into your domain.

The day the upstream system renames a field or adds a new variant, you change one mapping function instead of touching the entire codebase.