The tech in their stack is still pretty good. Unless you’re supporting tens of thousands of customers and trying to make the promises that fly makes today. Look at the fly engineer replies in this thread.

Also they basically only use OSS versions, they could go give Hashicorp some money to solve their Vault problems. They could probably partner with SecondQuadrant for PG as two examples. That might not make sense for their business though.

Hard problems are hard no matter the choice.