My team used java in two cases: BigInteger or 'isProbableTime.' For everything else performance penalty was almost always unacceptable. C++ can also be sometime

My team used java in two cases: BigInteger or 'isProbableTime.' For everything else performance penalty was almost always unacceptable. C++ can also be sometimes finetuned enough to pass with unintended complexity (i.e. O(n lg n) instead of O(n)).