Why Even Signal Calls Apple & Google (gpn24)

I just wanted Zulip notifications on my phone. So I started building something myself - and fell into a rabbit hole. This talk tells the story of how I tried to solve a problem - and in doing so, understood how push notifications actually work. Why my first approach didn't scale. Why almost every app uses Firebase or APNs. Why even Signal knocks at Google's door. And why, since the Wyden letter of 2023, this is a documented privacy problem: "We kill people based on metadata." I'll show what alternatives exist with UnifiedPush and ntfy, how I built a bridge for Zulip, and why the same problem applies to your Prometheus alerts, Grafana notifications, and CI/CD pipelines. And what all of this has to do with digital sovereignty. Licensed to the public under https://creativecommons.org/licenses/by/4.0/ about this event: https://cfp.gulas.ch/gpn24/talk/38ZLSX/