I don't think that distinction matters. Libraries can easily encapsulate data. I think he's right - microservices are very often used in situations where a lib

I don't think that distinction matters. Libraries can easily encapsulate data. I think he's right - microservices are very often used in situations where a library is clearly the right tool for the job. In my experience the main reasons people don't use libraries are: a) the people in charge of the place where you should put the library are too territorial, so it becomes easier overall to start an entirely new project and deal with the very large downsides of microservices, and b) they want to use a different language, and disappointingly FFI over HTTP is usually easier than "true" FFI.