because the Internet of things backend b has already provided rest api, my project wants to use the rest api interface provided by the Internet of things backend b, but I also hope that some business logic can be managed independently on the backend a.
because my idea is that the front end initiates a request to the background a, the background a does some simple processing, and the background an initiates the request to the Internet of things background b. After the background b processes, the result is returned to the background a, and then to the front end

so is this front-end-background a-background b mode reasonable?
does this approach have some advantages over the front end connecting directly to the Internet of things background b?

if deployed. If background an and background b are placed on the same machine, can the problem of transmission delay be ignored?