Well, I run a small SEO company and there are two ways companies generally go about it. The first way, they hire a few people who specialize in particular areas. For instance, they would hire a keyword analyst, article writer, link-submitter, video marketer, social media-er etc. While other companies train SEO's from A-Z, for every component involved. Keep in mind though, there is a stack of info out there and only so many brain cells per person. Here you will get more information about new york seo.