You don't have to give up clean code to achieve high performance. The complexity can be isolated and contained. For example, take a look at ClickHouse codebase

You don't have to give up clean code to achieve high performance. The complexity can be isolated and contained. For example, take a look at ClickHouse codebase: https://github.com/ClickHouse/ClickHouse/ https://github.com/ClickHouse/ClickHouse/ There is all sort of things: leaky abstractions, specializations for optimistic fast paths, dispatching on algorithms based on data distribution, runtime CPU dispatching, etc. Video: https://www.youtube.com/watch?v=ZOZQCQEtrz8 https://www.youtube.com/watch?v=ZOZQCQEtrz8 But: it has clean interfaces, virtual calls, factories... And, most importantly - a lot of code comments. And when you have a horrible piece of complexity, it can be isolated into a single file and will annoy you only when you need to edit that part of the project. Disclaimer. I'm promoting ClickHouse because it deserves that.