> The idea that you can have either best practices or performance is a false dichotomy. Testing can be used to help track down performance issues. It can help y

> The idea that you can have either best practices or performance is a false dichotomy. Testing can be used to help track down performance issues. It can help you write code faster and prevent breakages. It should not slow you down. It orks the other way too. Benchmarking can show that your bottleneck is virtcalls/boxing where you have used an interface field instead of a static instance to a concrete dependency. The argument isn't "performance vs. tests" it's really "performance vs modularization". You can always move the tests upwards until you test the whole monolith. This isn't a common tradeoff but I also wouldn't dismiss it as something that never occurs and "best practices" wrt. modularization and unit testing always enables similar performance. It doesn't.