Comment by littlecranky67

Sounds like a regular setup, at least this is very common in modern C#/.NET when you implement REST services. Nothing to do with Hexagonal Architecture, just inversion of control. There is a very thin DI container baked into ASP.NET and the pipeline. Do you have to use that? No, but it gets complicated very quickly if you don't. So any project that is more than a tech demo/eval uses DI. In other languages/frameworks (i.e. Typescript+NodeJS) this is not very common for some reason.