Memory usage is still terrible with Java but at least there are plans to address part of it with value types etc. But for a web service performance is pretty go

Memory usage is still terrible with Java but at least there are plans to address part of it with value types etc. But for a web service performance is pretty good (just look at techempower benchmarks and the fact that most high scale companies use Java for a significant part of their infrastructure). If you need to talk about startup time you don't need scalablitiy or really want a different solution/architecture.