I am using Kotlin with Quarkus for my healthtech startup (founded last year), mainly because it just works. JVM is a very optimised piece of software, and it can handle almost anything you throw at it. And I like writing Kotlin, which I think is more expressive compared to something like Go, while being less verbose than Java. Contrary to popular opinion of not touching ORMs, I use Hibernate, and it might be the best ORM available. None other ORM library comes close - but that's just my opinion. Sure, I can handwrite SQL queries, but as a startup, my data schema is always changing and I don't want to spend my time updating those raw queries when Hibernate can do it for me. I use it at my day job as well.