it's not just the top tier engineers. It's engineers who are confident enough to take flyers on startups. It also helps they're very confident that if the sta

it's not just the top tier engineers. It's engineers who are confident enough to take flyers on startups. It also helps they're very confident that if the startup explodes they'll be able to get another job; that requires a density of opportunities and employers who don't mind a previous job that blew up or a short stint or two.