>Would be curious to know how they tried to optimise the Java stack.
Fairly safe to day not at all.
The JVM is extremely fast, very efficient and very scalable (you can write java code that scales linearly with available cores). If performance or scalability is a metric to care about, it is nearly impossible to outscore java. You can, with very skilled C/C++ developers, but it's going to be difficult to find those people and it'll be a lot of work. If you need extreme performance on a reasonable budget, you can't do better than java. I know java isn't hip anymore, so this is not a popular truth, but it is.
Fairly safe to day not at all.
The JVM is extremely fast, very efficient and very scalable (you can write java code that scales linearly with available cores). If performance or scalability is a metric to care about, it is nearly impossible to outscore java. You can, with very skilled C/C++ developers, but it's going to be difficult to find those people and it'll be a lot of work. If you need extreme performance on a reasonable budget, you can't do better than java. I know java isn't hip anymore, so this is not a popular truth, but it is.