Having a monolithic business application with complex business logic implemented in Visual Dataflex, we are facing the challenge of maintaining our business logic across programming languages as certain features are written in other programming languages (mainly .NET).
So I am looking for strategies to "synchronize" business logic across different programming language implementations, in order to avoid mismatches. Avoiding duplication is a plus, but this may be compensated by automated testing.
EDIT: SOA is a great suggestion. But what about those cases where a service will not be fast enough?
EDIT 2: Any suggestions for using a metalanguage?
Looks like you're looking for Service Oriented Architecture (SOA). With SOA, you can define your business logic as Services, which can be called from any program, in any language. When the business logic changes, change your Service and the behavior will change in everything that uses it. SOA also minimizes code duplication, because the logic only appears in one place (the service).