VELD: Versioned Executable Logic and Data, a design pattern for reproducible and flexible workflows

VELD is three things: a design pattern, a reference implementation, and a platform. Its goals are standardized creations of workflows that are both flexible and reproducible. It proposes a modular architecture, based solely on git and docker, by defining interoperable components that can be aggregated into reproducible cohesive workflows or be easily rearranged and reused across contexts and machines. As a design pattern, its ideas can be interpreted more loosely and implemented with any suitable technology, with no constraints other than the definition of the constituting VELD objects and their relations. The second section of this concept proposes a reference implementation detailing stricter requirements regarding choice of tools, metadata syntax and procedures. Finally, the third section elaborates on a possible web platform to browse, find, publish, and execute veld objects.