Personally, I have a scraper service, web app server cluster, stream server cluster, mobile service, and a data access layer in my setup. They all communicate

Personally, I have a scraper service, web app server cluster, stream server cluster, mobile service, and a data access layer in my setup. They all communicate with each other, but in very different ways. The scraper for example uses fire and forget to send something to the data access layer. The web app cluster needs to use the request reply model with the data access layer. The data access layer needs to send pub / sub messages to the stream clusters holding live connections. I also have a mobile service which does a combination of pub / sub (notify stream servers), req / rep (data access), and fire / forget (analytics). I needed one library with a 1 line install that handled all of these cases, with the simplest API I could come up with.