Functions as a service (FaaS) have really become a staple in most development circles. They provide little infrastructure overhead in the development of microservices and are often very lightweight. Yet FaaS face their own sets of challenges when it comes to costs, response times, and observability.
I believe that architectures will evolve over time. In some cases you may never want to change your FaaS but there may be cases that you’ll want to move it to it’s own application.