[arnold_palmur]

At least in terms of open-source, I often say that the Aeron code base is one of the best projects to study in terms of software quality (especially Java). The real-logic (now Adaptive) guys are a skilled and knowledgeable bunch.

[pgwhalen]

It’s a superb codebase for sure, I’ve spent dozens or hundreds of hours reading it. But I would caution against using it as an example of Java the language because of how non-idiomatic it can be to achieve the absurd performance it does. Most Java shouldn’t use a lot of the techniques they use (and the authors would be the first to admit that).