At Zendesk, I work on a Ruby Platform Core team: we create solutions for common problems, help teams with upgrades of Ruby and Rails, write guides, and create tooling for this work.
Outside Zendesk, I work on improving ChGK (think of it as a more competitive pub quiz with better questions and about 10k monthly active players in ranked tournaments; see Wikipedia), which includes things like the official ranking system, a fantasy game, and a bot for selecting the best questions of a year.