Maybe I'm wrong, but I think you're missing it. Microservices, at least how I understand them, is just functional programming at the O/S level. Where they are

Maybe I'm wrong, but I think you're missing it. Microservices, at least how I understand them, is just functional programming at the O/S level. Where they are located, how they talk to each other, and so forth? That all becomes SysOps stuff. That's good and bad. It's really bad if you don't stay on top of it and don't refactor. You can make the same mess you made in your big monolithic POS, just spread out everywhere. But to state it that way misses the point. The point is to actively keep the number of microservices small, have tests for each one for compilation, deployment, and production. You should never deploy something that doesn't work in the ecosystem. The development environment should prevent it. You should also have a very good grasp on data flow between microservices and latency issues. Monitoring that should be part of your daily work. You don't just do microservices because they're cool. You do them because they separate concerns in such a way to be both scalable and configurable without having to touch the IDE. With good safety protocol in place, this decrease both risk and complexity. Without good protocols in place, you'll make a mess no matter what tool you're using. Look at it this way (put your FP hat on): any program takes input, runs it through some functions, and produces output. If you were debugging, you'd set up breakpoints along the inputs and outputs to chase down errors. Then you'd walk the data flow to see what was going on. Microservices allow you to do this without touching the code. You would think that this increases network and system instability. It can, but when done well, you get the same thing you had with the big monolithic thing -- only in smaller pieces that you can change and reason about without introducing one of the thousand stupid coding errors that get introduced any time we open the project up and touch it. Plus you get hot-swapping, easy testing, auto-scaling, and ease of programming. In the modern VM/hosted world, this is a pretty good trade-off.