A new approach to web application development is presented, in which an application is constructed by configuring and composing concepts drawn from a catalog developed by experts.

A concept is a self-contained, reusable increment of functionality. Each concept includes both front-end and back-end functionality, and exports a collection of components—full-stack GUI elements, backed by application logic and database storage. To build an app, the developer imports concepts from the catalog, tunes them to fit the application’s particular needs via configuration variables, and links concept components together to create pages. Components of different concepts may be executed independently, or bound together declaratively with dataflows and synchronization. The instantiation, configuration, linking and binding of components is all expressed in a simple template language that extends HTML.

The approach has been implemented in a platform called Déjà Vu, which we outline and compare to conventional web application architectures. We describe a case study in which a collection of applications previously built as team projects for a web programming course were replicated in Déjà Vu. Preliminary results validate our hypothesis, suggesting that a variety of non-trivial applications can be built from a repository of generic concepts.