You should check out multi-document ACID transactions on MongoDB 4.x. (Yes things have dramatically changed... add in change streams and JSON schema validation and $lookup and $graphlookup in aggregation)... (And if you don't want to install it locally, try a free M0 on MongoDB Atlas to play with the new features).

And yes, I work at MongoDB, and I worked with it before and it has really changed - WiredTiger has been a game changer for it, which is why I work at MongoDB now.