Build Video Activity Alerts for Your Next.js App

Streamed on Mux’s channel with Dave Kiss. The framing is a question everyone has already answered for themselves without noticing: how does the YouTube bell know to light up?

We build it against a fictional app — MyTube — and work outward from the easy version. Mux fires an event webhook, Knock turns it into a notification. Then the parts that actually decide whether the feature is any good: batching so a busy channel doesn’t send twenty emails, subscriptions so people only hear about creators they follow, and preferences so they can turn any of it off.

Six weeks later this became a written guide on Mux’s blog.