David Heinemeier Hansson, widely known as DHH, is a Danish programmer best known as the creator of Ruby on Rails. On his personal site he describes himself as “the creator of Ruby on Rails… co-owner of 37signals, best-selling author,” and identifies Rails as “the open-source web framework that I created in 2003.”
Rails grew out of real product work. Hansson built it while developing Basecamp, a project management application, for the company 37signals (later renamed after its flagship product). Rather than designing a framework in the abstract, he extracted Rails from a working application, and that origin shaped its strongly opinionated character. Rails was first released as open source in 2004.
In The Rails Doctrine, which Hansson authored, he lays out the philosophy behind the framework. He stresses optimizing for programmer happiness, writing that “I created Rails for me. To make me smile, first and foremost.” He pairs this with convention over configuration, the idea that a framework should supply sensible defaults so developers do not have to make trivial decisions, captured in his blunt line “You’re not a beautiful and unique snowflake.”
These ideas, programmer happiness and convention over configuration, spread well beyond Rails and Ruby. They influenced a generation of web frameworks in many languages that aimed to let small teams build complete web applications quickly, and they made Hansson one of the most visible and outspoken figures in modern web development.