Polling is the first thing everyone builds and the last thing anyone is proud of. Here's the migration, the code, and a way to measure your own before/after instead of trusting mine. Every live scoreboard starts the same way. You write a setInterval, hit an endpoint every few seconds, diff the response, and update the screen. It works on day one. It keeps working right up until someone watches a goal on TV and then waits several seconds for your app to catch up. I moved a live-score featur...