How many of you out there have to deal with integration within your applications?  By integration, I mean either logic or data.  When it comes to logic integration, your application calls a local/external service to perform logic that’s not part of the system.  For example, in your business process, you call an external web service to perform a computation with your data.  As for data integration, your application takes data that’s been processed and moves it to necessary data stores (database, files, etc.) that need it.  An example of data integration is the replication of data accross data stores or the retrieval of data from different stores under a common schema.  At times, an application can perform a mixture of these types of integration to perform its tasks.

I’m curious to find out how you have managed to solve this very common business need.  Feel free to list patterns, experiences (good or bad) you’ve had with your ventures.