Socket.IO

Your tech stack is solid for building a real-time messaging project.

React and React Native are excellent choices for the frontend, especially if you want to have both web and mobile versions of your application share code.

ExpressJS is an unopinionated framework that affords you the flexibility to use it's features at your term, which is a good start. However, I would recommend you explore Sails.js as well. Sails.js is built on top of Express.js and it provides additional features out of the box, especially the Websocket integration that your project requires.

Don't forget to set up Graphql codegen, this would improve your dev experience (Add Typescript, if you can too).

I don't know much about databases but you might want to consider using NO-SQL. I used Firebase real-time db and aws dynamo db on a few of my personal projects and I love they're easy to work with and offer more flexibility for a chat application.

Key thing to understand here is that you are hosting data & logic somewhere. Socket.IO requires you to host and manage a dev server somewhere (as the previous suggestion mentioned Heroku is a good choice)

However, It's not really in keeping with the serverless world that Vercel provides and its a headache to scale and manage. We (I work at Ably) have a bunch of open source examples of how all this works. Ably provides serverless N to N connectivity, along with first class integrations into serverless functions on AWS, Azure, cloudflare and GCP. This allows you to build a realtime, serverless system that you can scale without any pre provisioning.

Nothing is totally free but you can get away with the free tiers on all of these services for a lot longer than you may think.

It really depends on how you want to do it. If you use Socket.IO, you do have to have your own server running somewhere else, a good free one is Heroku. Pusher is nice if you know what you are trying to do, know your limits, and how to do it. While Socket.IO allows more flexibility if you need to do something crazy, Pusher is great if you're just doing standard real-time data transfer because there is minimal setup. The only other thing about Pusher is that it is not entirely free, so if you know the pricing, know how much you are going to use, and are willing, you could easily use Pusher.

I would recommend looking hard into Firebase for this project, especially if you do not have dedicated full-stack or backend members on your team.

The real time database, as you mentioned, is a great option, but I would also look into Firestore. Similar to RTDB, it adds more functions and some cool methods as well. Also, another great thing about Firebase is you have easy access to storage and dead simple auth as well.

Node.js Express MongoDB Socket.IO and Apollo are great technologies as well, and may be the better option if you do not wish to cede as much control to third parties in your application.

Overall, I say if you wish to focus more time developing your React application instead of other parts of your stack, Firebase is a great way to do that.

Hello Noam 👋,

I suggest taking a look at Ably, it has all the realtime features you need and the platform is designed to guarantee critical functionality at scale.

Here is an in depth comparison between Ably and Firebase

I would recommend Amazon Chime. If I were you, I would eventually look into working with WebRTC as it is very interesting and teaches you a lot. I dove deep into webRTC recently building a webinar broadcasting application (one-to-many) and I can say it is difficult to understand how things actually work and to get it stable. I mean you can vaguely read up on it and get some things to work by copying code on StackOverflow or using a library but that wouldn't teach you much.

In short, go with Chime because it is easy to get started especially if you have a time constraint. But look into webRTC in the future as it enables you to build your own "Chime". Hope this helped!