- prepare good documentation
- be on a call with them when you have to explain stuff verbally
- be available in text chat to answer their questions
No need to be always on call like this.
I can only imagine this being used as yet another control tool for paranoic managers who want to make sure employees are always "working" at the desk.
That's already out of the question in most companies I worked for that weren't established in a field like automotive, robotics, medical, aerospace.
All web dev companies I know have their documentation in slack chats and in the heads of the senior devs with longer tenure who setup the greenfield, as their main incentive is to concentrate their efforts to ship-ship-ship to get features/sales/customers, not spend time writing docs that get outdated in a couple of sprints.
Needless to say, being a junior in such a place is demoralizing AF as you don't understand anything and by the time you think you're there, the goalposts have moved again.
I came into the one company replacing a Flash application. We used BackboneJS first, then realized Angular was a better fit for larger applications, then a few years later when the whole company was basically using Angular, some guy came in from Google and Decided that they should be using Polymer instead. Once they nearly had everything ready for Polymer 2, Polymer 3 and lit-element came out which, of course, was completely different.
I mean we spent time there fixing a performance issue because unlike real UI frameworks, Polymer had no real concept of routing; in effect it worked like tabbed web interfaces, leaving things open but hidden as the user navigates away.
It was a multi-million embarrassment. I spent 2.5 years there in total in the Backbone and Angular project, and they decided fuck you, we'll do it different because we have a new UI style now so obviously every application has to be rebuilt from scratch.
It is difficult enough to overcome the curse of knowledge when writing documentation that a better path is to open up a pair-programming setup and co-write your documentation with an intern or new-joiner.