Orchestrating different bounded contexts, whose responsibility is it?

Question

I have 3 separated services using different databases with REST interfaces:

• First service: Information about Customers
• Second service: Information about Customer Trades
• Third service: Information about Customer Documentation

Problem: Every customer has a Status that should be evaluated based on his trades and documents.

Which service should be responsible for this evaluation and how should I implement the orchestration between the other services?

Answer 1

If you can, I'd create a 4th service. This way you have a service that returns what you need, avoiding the problem (and over chattiness) of calling 2 services and merging the result set. Otherwise, if you don't have access to be able to create a 4th service, maybe write a proxy service that through one call, calls the other 2 services and uses data caching to cache data where possible, to try help cut down on multiple calls in the future for commonly queried customers.