In-app notifications, shipped as a bell icon

The feature request has 41 votes: "in-app notifications." Every SaaS gets there eventually. The standard route is a notifications table, a read-state column, a delivery pipeline, a bell icon, and regret.

Each of your customers already runs in their own container, and every container carries a notification server. Your backend POSTs /api/v1/notifications/notify with a category per event type; the customer's browser holds the stream, so the bell updates without polling. History is the inbox: it was being recorded anyway. Read state is POST /api/v1/notifications/dismiss; a DELETE marks it unread again.

You ship the bell on Friday. The table, the column, and the pipeline never get built, because the substrate had built them already.

Every customer's container came with a notification center; you shipped the bell.