Leveraging Mono.zip appropriately will [with the right configuration] lead to a high amount of performance and concurrency. There is one caveat to its usage though:

Reactive Programming is a very different way of thinking about doing work in a microservices environment. Anyone who has worked with a GUI, dating back to even to windows forms, is familiar with the event based model, but what does that mean when there is unpredictable latency involved? How does handing off to a thread to make a remote call differ from this new “reactive web”?

Spring Boot’s WebFlux programming model is pretty neat, but there isn’t a lot by way of explaining how to best leverage it to get the results you need. I wrote this blog post after tinkering with the configuration of Reactor Netty on Spring Boot.

The source code for this post can be found on GitHub.

When you’re in a microservice environment, it often makes sense to make some calls to multiple services at the same time. This allows for the time an operation needs to complete to be reduced from the sum of all the time spent waiting to the maximum time spent over the span of calls.