I've been working with Drupal since 4.7. In my freelancing days, I wore a lot of hats: SEO, front-end, sysadmin, etc. But for the past 4 years, while a developer at NPR, I've focused on the back-end, with some ad-hoc dev-ops thrown in as well.
Until recently, I was the lead developer and architect on Core Publisher. But I now concentrate on content strategy, the NPR API and the very new Public Media Platform -- as well as integrating all of these into Drupal.