How long should it take to know if your code is safe?Martin Fowler once said: 10 minutes.Ten years later, five hundred developers agreed.I disagree���with all of them.First, ten minutes is not enough for a proper build, even for a small software system.Second, ten minutes is too much for a build that we run from the IDE after every one-line edit.We need a finer-grained classification of builds: from bullet-fast to thorough and dead slow.

How long sho...