You use special libraries designed for this purpose, that use a static buffer under the hood themselves. Or you just make sure that memory usage increase is low

You use special libraries designed for this purpose, that use a static buffer under the hood themselves. Or you just make sure that memory usage increase is low enough that it isn’t a problem. You sometimes have places where they do for example one GC call a day. Take a look at https://github.com/OpenHFT https://github.com/OpenHFT to get a taste of what Java + HFT looks like.