the current project needs to call multiple external systems, unify the return values of all the interfaces, and return to the front end.

question

• the return values of multiple external systems are quite different. Using factory, adapter and other modes, you can be forced to integrate, but the implementation complexity is relatively large, and it is not easy to expand in the future (continue to add external system access). Are there any other ways and solutions that can be expanded more easily?
• requests multiple systems at the same time, with different response times for each external system, but returns at the same time. The fork/join model is adopted to achieve simultaneous access, and then a circuit breaker mechanism is added to ensure the final response time. This is our plan. Is there a better one?.