I've been developing web apps for a few years, as have most of the others on the Ushahidi team. I've started a series on my own blog about the three areas that we're never good enough at: speed, stability and simplicity. All three are a constant pressure that sits on every one of our development cycles, and for which we dedicate a great deal of energy. All three are about user interaction with the application, because in the end that's what makes or breaks the application. The first post and story is on speed. I'll update this blog post as I get to stability and simplicity in the coming week.