non-call

non-call is a browser-based on-call simulator hosted at serum.sh. It presents a compact interactive experience built around the familiar scenario of being paged in the middle of the night, as suggested by its tagline about having played this before at 03:12 in real life.

The site’s core feature is the simulation itself, which walks the visitor through an on-call incident in a narrative, game-like format. Rather than offering dashboards or documentation, it focuses on mood and recognition, using the shared experience of late-night alerts as its subject matter.

It is aimed primarily at software engineers, SREs, and operations staff who have lived through on-call rotations, as well as anyone curious about what that experience feels like. The humor and framing assume some familiarity with paging and incident response.

To use it, simply open the page and play through the short scenario; no account or setup is required. Treat it as a brief, reflective diversion rather than a training or monitoring tool. Overall, non-call is a niche, well-observed take on a common engineering ritual.