Appsmith is currently is built for a single-user editor experience. If you try to update the same page/widget/action from two different places, it will overwrite each other and will lead to a loss of work. We recommend that at a given time, only one user is editing a page in a single open tab. Multi-user editing is on our product roadmap for 2022.
Alternatively, Appsmith supports Version Control with Git, users can work on multiple branches of an app simultaneously.
Read more about Version Control with Git here: