None of those three sentences lead to the next. Don’t blindly think that Julia is the best tool for every job — it’s not. If it is the best tool, then it’ll be obvious how you should be using it. Microservices are themselves just another tool — not one that I’d say Julia would excel at — but similarly people don’t go around looking for ways to build microservices.
Julia is a great tool that I enjoy using. My Milwaukee M18 Oscillating Multi-Tool is also a great tool that I enjoy using. But I don’t go around looking for things to cut holes into because I want to use the thing. And I don’t use it to whack on nails.
Code does something and has a purpose. Find something you want to build and use the best tools to accomplish that. Sure, you could filter the “what to build” based on how much you think you’ll enjoy building it, but you don’t use tools for the sake of using tools — especially not at your day job.