If you’re really after raw latency, C++ is still king because you can pin everything to the exact memory layout you want and tune it to the last CPU cycle, but you’ll spend a lot of time wrestling with the compiler and debugging memory bugs. Rust gives you a similar speed with a safety net that keeps you from accidentally dereferencing null pointers, and its async model can help you keep throughput high without the thread‑pool overhead of C++. Go is the easy‑to‑write option, and its goroutine scheduler is good for throughput, but the garbage collector can bite in the middle of a trade. So for the trade‑off between developer sanity and the absolute lowest latency, I’d pair Rust for the core matching engine and Go for the order‑routing layer, keeping the codebase small enough to review in a single night.

Fine, as long as the reviewers don’t get lost in the diff maze. Tight code, tight schedule, and a debug watchlist longer than a coffee break.

Alright, diff size is a good metric for sanity, just make sure the compiler still sees all the optimizations you need. Keep the code concise, and the trade window closed before the coffee breaks.