Pusher

For the mobile app we decided to use React Native and Pusher for the chat messaging

Recently we finished long research on chat tool for our students and mentors. In the end we picked Mattermost Team Edition as the cheapest and most feature complete option. We did consider building everything from scratch and use something like Pusher or Twilio on a backend, but then we would have to implement all the desktop and mobile clients and all the features oursevles. Mattermost gave us flexible API, lots of built in or easy to install integrations and future-proof feature set. We are still integrating it with our main platform but so far the team, existing mentors and students are very happy.

In the original prototype all the communication was handled by a backend server. Each client connected directly to the server using the socket.io library. This quickly proved to be messy and unreliable, especially on the cheap server being used to host it.

Websockets proved to be a little more reliable, but still just as messy and not all browsers support them. That's when the project was switched over to use Pusher. Using Pusher has allowed all but the initial connection code to be off-loaded onto the client. Now instead of communicating through a self-hosted server, clients can communicate pretty much peer-to-peer over Pusher. Pusher

Pusher is used to send update notification whenever Lapzbot joins a server. Pusher