Yes we have two datacentres and we do have a few VPS mostly for triangulation of monitoring, but honestly, in four years - we haven't had to failover once, although we practise it with our applications almost every single day.

Thank you for the kind words there, I think one major thing for us is that we've hired a small number of just the right people, each with quite different backgrounds and we work VERY closely with our developers. Every bit of configuration is kept in GIT and we CI / CD whatever we can.