Problem
A hospital's day queue ran on manual calling and paper numbers, with no shared view of who was next across the reception desk, service counters, and waiting area. Staff at different stations couldn't see the same queue at the same time.
Approach
I built DayQueue as a networked, multi-PC queue system on Node.js, Express, and WebSockets. It has three coordinated views: reception issues tickets, counters call and serve them, and a public display board shows the queue. Every change is broadcast instantly over WebSockets and persisted to disk so the queue survives restarts. Tickets carry client names for staff while the public board shows numbers only, for patient privacy. It's self-hosted, managed with PM2, and secured behind HTTP Basic Auth and Cloudflare Tunnel with Access.
Result
DayQueue is deployed and running on my own infrastructure, keeping every station in sync in real time. Along the way I traced a silent failure, where connections looked live but updates never arrived, to a file-permission error on the state file. I then added a migration path so older saved queues stay compatible as the data model evolves.