I think certification is essentially the same thing as having someone else interview the candidate, so it won't be better and is easier to game than interviews. Working together with someone on the kinds of problems you actually face is the most realistic way to assess a person's abilities on the work to be done because it's less of a proxy than anything else.
Yeah kind of. I think of it like DRY though. Most people aren't good at interviewing. Everyone does some random thing they think is better then the rest. But really it's uninformed. Just like you wouldn't implement your own hash map for most cases, you don't need to do a technical interview for everyone. I had one company do three seperate coding rounds. How many candidates do they have, what a waste of time for everyone.
