Consumer hardware is totally fine if you use multiple machines - the probability of them failing at the exact same time is very low. His stack already uses mul

Consumer hardware is totally fine if you use multiple machines - the probability of them failing at the exact same time is very low. His stack already uses multiple appservers (so the loss of one wouldn't even be noticeable) and has a manual way of failing over to a DB replica. It's often cheaper to work around node failures (which you often need to do for other reasons anyway - DC-wide outage, etc) than have more reliable nodes.