It had both compute and storage (netapp). It had two twin sites in two different datacenters. The infra in each site consisted basically in six compute servers (24c/48t, 128gb ram) and netapp storage (two netapp heads per site + disk shelves).
Such hardware has basically paid itself across its seven or eight years of life, and having one of the sites basically in the building meant basically negligible latency.
The workload was mostly fixed, and the user base was relatively small (~1000 concurrent users, using the services almost 24/7).
It really checks all of the boxes, does all it is supposed to do and in a cheap manner.