Thermopylæ is a one of a kind live temperature dashboard written for a friend who had built their own home monitoring system. The service, built in Django, regularly runs a job which fetches the latest temperatures which are shown on the dashboard. At the end of each day, another job runs which performs rudimentary analysis on the days readings, so that the raw readings can be discarded.
Somehow this service has been running without interruption and very little maintenance for half a decade. I don’t even think the friend is still using it.