End user programming, a frequently recurring dream, has thus far eluded large-scale, complex applications. Very real, hard questions stand in the way of its realization. How can its languages and tools support:

• The development of applications with large data sets and sophisticated computation?
• The co-development by end-users and professional developers when the complexity of an application demands it?
• Beyond development, the maintenance, distribution, monitoring, and integration with other applications and services?

We discuss our approach to these questions, as implemented in the LogicBlox Modeler. We discuss its use in developing applications for governments, major financial institutions, and large global retailers. We highlight the essential synergies between Programming Languages and Database research to achieve self service at scale, and present open questions we look to the SPLASH community for inspirations and solutions.