My advice: • Make push updates optional. If no push connection can be established, fall back to polling. You can start by implementing polling only and add pus

My advice: • Make push updates optional. If no push connection can be established, fall back to polling. You can start by implementing polling only and add push later. • Use websockets only for server-to-client communication. Messages from the client are sent via regular HTTP requests. • Keep no meaningful state on the server. That includes TCP connection state. You should be able to kill all your ec2 instances and re-spawn them without interrupting service. • Use request/response for all logic on the server. All your code should be able to run in an AWS lambda. • Use a channel/subscription paradigm so client can connect to streams they're interested in • Instead of rolling your own websocket server, use a hosted service like pusher.com or ably.com. They do all the heavy lifting for you (like keeping thousands of TCP connections open) and provide a request/response style interface for your server to send messages to connected clients