There's a good lesson in operability here: log reasons for decisions! I have had to re-learn this lesson over and over again with my own software. "Tom, why di

There's a good lesson in operability here: log reasons for decisions! I have had to re-learn this lesson over and over again with my own software. "Tom, why did the system just do that?!" scream my users. "Er, let me check", i respond, already feeling that sinking feeling. "EDUNNOMATE" says the log. So, i add some logging around the decision (the data feeding into it, the choices made, the actions resulting), redeploy, and wait for my users to start screaming again, hoping that this time, i will be able to give them an answer.