Please fork this gist and use as your own checklist as you develop/deploy your web application or api.
WARNING: This checklist makes an assumption of the level of expertise and experience of the reader and assumes significant in-depth knowledge and experience in web development.
In a perfect world, where things are done well, not just quickly, I would expect to find the following when joining the company:
Documentation
Accurate / up-to-date systems architecture diagram
Accurate / up-to-date network diagram
Out-of-hours support plan
Incident management plan