DCEO allows you to create a company in a chosen jurisdiction (e.g. Delaware, US), and has an opinionated Shareholders Agreement and Company Constitution. From there it allows you to take actions that are allowed via the agreements and the system manages them for you such that it complies with the agreements set out. For instance, you can do share sales digitally, where the system is sending out letters to the various parties (including preemptive rights etc), you are putting in entries for acceptance, number of shares purchased, it’s basically guiding you through the process similar to how an accountant or lawyer would.
This is probably a bit like stripe atlas, but I think stripe atlas just helps you set things up, as opposed to actually helping you do share issues and things like that.