I’d say Java - most of our stack is in Go, but when it came to a modeling / business rules problem I found it easier to jump to Java 8+ (streams, lambdas), Auto

I’d say Java - most of our stack is in Go, but when it came to a modeling / business rules problem I found it easier to jump to Java 8+ (streams, lambdas), AutoValue for immutable objects, Google Guava for immutable data structures and built in ForkJoin system for easy concurrency and parallelism. It’s super easy to use all cores even when just using streams, which is superb.