You can have voting systems in place, where at least 2 out of 3 different code paths have to produce the same output for it to be accepted. This can be done wit

You can have voting systems in place, where at least 2 out of 3 different code paths have to produce the same output for it to be accepted. This can be done with multiple systems (by multiple teams/vendors) or more simply with multiple tries of the same path, provided you fully reload the input in between.