I'm pretty sure the UK does have actual software with actual databases backing up test and trace, some of which was outsourced - in fact it looks like our opposition party and opposition media are trying to blame this failure on outsourcing, even though that has no foundation in reality, mostly because this plays well with their supporters for reasons too tedious and political to explain. Unfortunately, this happened at a kind of interface between different systems designed to take in results from both the Pillar 1 NHS testing and Pillar 2 Lighthouse testing for the general public, deduplicate them, and spit them out to the contact tracing system and the government dashboard. These are seperate systems run by seperate organisations for various not-so-interesting reasons to do with the structure of the healthcare system and the history of Covid testing in the UK.