I would advocate for Node. It seems you are trying to fill your stack with a front end, a back end, and a database, but don't know your database. based on that, I would advocate for the MERN stack. based on the MEAN stack: Mongo, Express, React, and Node. Frankly, it's about choice, and since you are going to use performance heavy and cloud heavy things like video chat, I'd advocate for Node over Express.