Greenspun’s 10th rule states, “Any sufficiently complicated C or Fortran program contains an ad hoc, informally specified, bug-ridden, slow implementation of half of Common Lisp.” This has morphed into the newer joke: “Every microservice architecture contains a half-broken reimplementation of Erlang.” I think there is a lot of truth to this.

Related comments from the peanut gallery:

The architecture of an idiomatic Erlang-based system is essentially a microservice architecture.

If you have good abstractions for concurrency then distribution and independent scalability should be trivial in a single codebase. Loose coupling is usually a false dream. Microservices tend to get coupled at the network level instead of the code level. Yuck!