>Undo is a particularly challenging feature to implement in a structured relational database context, because it can't be reduced to a set of simplistic charact

>Undo is a particularly challenging feature to implement in a structured relational database context, because it can't be reduced to a set of simplistic character insertion operations as is the case for a google word doc, or a spreadsheet. I personally hit this roadblock while trying to build a revision management system for a spreadsheet like Google Drive has. I had a pretty fragile implementation that works within a tangled mess of has-many relations. It was a tough time generalizing the whole mess. I'm looking forward to your insights on this particular problem on your future developer blog! Congratulations.