I find that the boundary creates operational headaches. A function call won't time out, deliver a 502 error, have authentication/authorization issues, require l

I find that the boundary creates operational headaches. A function call won't time out, deliver a 502 error, have authentication/authorization issues, require load balancing, etc. etc. A REST API will. Plus, once you've debugged a problem that involves crossing 5 microservice boundaries you'll start to wonder if it was all worth it. Monolith is also a wrong (and somewhat derogatory) word to describe a non-microservice architecture. There's nothing monolithic about loosely coupled code running on the same machine. I really think that microservices are a hack to deal with conway's law in large corporations. Operationally it's inefficient but it fixes a nexus of technical and political problems when the correct boundary is picked.