Just like in Unix, we see the limits of composability: You can build some very basic, generic tools that are composable and easy to use. the greps and finds of the world. But there are relatively few of them out there, surrounded by a bunch of ugly, hard to read, hard to reuse glue. This is naturally occurring, because each piece of glue is not used many times, and its task isn't all that easy to define.

So, taking this to Microservices: while we can build a bunch of little services that will be reused everywhere. The large majority of a system will be this kind of glue: You can't make every single piece of code you write be as well defined as grep, but with a service interface. And while you will be able to track what the little pieces do, the bigger command and control pieces will always present a problem. We can't wish complexity away, no matter how hard we try.

So designing a bunch of microservices and hoping most of your problems will be solved is like trying to build something in Unix without perl and shell scripts. But I see companies, today, that think it's a silver bullet. They've not read Brooks enough.