Maybe not a surprise, but definitely unexpected, was the number of systems where, over time, the incremental features had overtaken the original architecture, but the vendor would not fund a new implementation. I've seen 15 year-old systems that were so byzantine, every feature change broke two others, and attempts at improvement caused entropy. It was both a huge time sink and customer satisfaction debacle.

Here is an idea for CSCI 344: Identifying When to Throw that Shit Out