SEO specialists, do you spend more time on the technical or marketing side of SEO ?

It appears SEO has two faces, one is technical (technical SEO, structured data, On page SEO) the other is more "marketing" (link building, keyword research, content). I looks like most of the technical side would be pretty basic stuffs for a developer and they should be familair with it when building a site for their client/company. So my question is, when working on a project, do SEO specialists or consultants spend more time on the marketing and strategic side or do they actually get to work with devs on building the site? or 50/50 ? It might be a stupid question for some of you guys but I'm new to SEO and would like to know.