The most important thing about hiring a developer into a team isn’t his commenting or code style — it’s matching his/her attitude toward software development with that of the team. If the team thinks that commenting and unit testing is super-important — then the candidate should too. If the team thinks that long variable names and communicating business value are the most important things, then the candidate should too. There are all sorts of engineers that succeed in all sorts of environments. The best engineers are the ones that fit their environment naturally. DHH is a very opinionated developer — and intuitively looks for people who share his opinions, because that’s how a team comes together.