One example of poor performance on my software is the SOAP 'Web API'. One request takes 1 second. Two simultaneous requests take 4 seconds. Three simultaneous requests take 9 seconds. Four simultaneous requests take 16 seconds... I know it does a lot of locking, but really just WTF is going on in there?

I am completely slating the design of this software, so I will throw in one good point and that is that miraculously it doesn't really crash (much). It tends to catch most exceptions, and so far its reliability is quite okay. I'm happy that there appears to be an accounting reason for having the accounting period configuration set up the way it is.

Back to 'Too many checkboxes' - I actually have a flag which I can set on a product which is 'Is Fish?'. I have no idea what this actually does.