My experience writing an bidder for realtime ad exchanges in Java -- which was a mistake driven by our use of some &#x27;legacy&#x27; code -- the numbers work out on average but not in the 90+th percentile. Heavy tuning of the GC yields  better results but there&#x27;s always something that comes along and causes burps.  Throughput is usually on average fine -- but the latency spiky.<p>If your problem domain is fine with that, that&#x27;s great. But I will never use Java for something latency sensitive again.<p>After I left that job I worked on the other side of RTB, on the exchanges themselves. They were both written in C++, and performance was reliable and awesome.<p>I would only use something like C++ or Rust for this purpose.