Pusher is an early example of this model. It came out of a hack day at a Ruby on Rails consultancy called New Bamboo, got spun out into its own business, raised

Pusher is an early example of this model. It came out of a hack day at a Ruby on Rails consultancy called New Bamboo, got spun out into its own business, raised VC, and then sold to MessageBird. New Bamboo got acquired by ThoughtBot some years ago.