QuantuMDx Software Engineer interview questions

A quick screening with a recruiter, then a single video interview with would-be coworkers and manager, so three other people on the call. Interview was quite quick and they offered me a job shortly thereafter. They then delayed giving me a contract and cancelled the job offer the day before I was due to start. Having accepted their offer, they claimed HR or the hiring manager were ill/busy/on holiday, presumably to defer giving any further information. The recruiter and I had to call and email them several times to get any information, and after 3pm the day before I was due to start, I received a very brief email saying the job was cancelled.