Building new things is exciting. Most developers jump at the chance to work on a project where they can create something from nothing. I get the appeal of not worrying about existing code and all the difficulties (technical debt, etc.) that comes with that.
The biggest mistake I see developers, and architects, make on new projects is not following up on the initial release to ensure all the needed support documentation and the just one more thing changes haven’t created an unnecessary amount of technical debt in the process.
No plan is ever 100% complete compared to what is built. That is fine. The important part comes at the end where you circle back as group and ensure things are maintainable and expandable.
Project Leads, leave some time for this recap and make sure any action items get assigned.
Developers, as you build your app, website, library or whatever – remember that whomever comes along next to improve or fix something doesn’t always have the time to figure out what you did, implied or didn’t document.