While a few seconds is unrealistically fast, if you ask me, I did notice that long testings duration is very detrimental to the quality and testability of a cod

While a few seconds is unrealistically fast, if you ask me, I did notice that long testings duration is very detrimental to the quality and testability of a code base. If you have to wait 1h for testing feedback it kills the development inertia. And so do slow development tools, compiling something for 2 h and then getting negative feedback is not cool, and yet this is something I've seen happen at my current job and it drives me insane.