Disclaimer: I love writing production systems in Java. I was a C++ programmer for 10 years before moving to Java about 15 years ago. Java offers a virtually all in one package when writing large systems. You have a single language where you can write code that doesn't care to be the fastest possible, and you just rely on ZGC to do its thing, and it works. Or you can write GC free code with a mostly quite performant SoA type approach. You can do this in the same codebase, and developers don't need to know different languages to write either style of code. You then have one build system, one deployment system, an incredible set of observability tooling, etc, etc.

So I might be biased, but with the correct curation of AGENTS.md files and skills, we're getting extremely good results using Claude Code writing Java.

Another disclaimer: I haven't tried with another language, but we're happy with the results.