Hi all

I know there's some decent material floating around relating to more specific areas, but wanted to get some opinions from people who have had bad experiences in the past.

I have a project where I can have a say on the design of a B2C web app, which has some external API interfaces. UX is crucial as is speed. Not sure what technology will be used at this stage.

In designing this application, I want to make sure obvious features are not left out (i.e. ones that make maintenance/development easier). So can you guys tell me about 'situations gone wrong' that could have been avoided had more consideration taken place?

Am looking to gather feedback in general, so don't worry if your example is industry/technology specific - so long as it pertains to web.

Thanks for reading, I look forward to your responses!