What is a Builder?* Init a builder data structure with a set of reasonable defaults * Customize those defaults through a series of chained function calls * Builders have the same type for the return type and final argument, so that they work nicely in a pipeline

Resources and Examples* Luke Westby's http-builder package * Brian Hicks' Robot Buttons from Mars talk * elm-review package docs * elm-pages/phantom builder live coding * Richard Feldman's Oslo Elm Days keynote