Various law schools-Chicago-Kent Law School, New York Law School, Vermont Law School, and Georgetown Law Center among them-are beginning to offer innovative classes in which students learn to build legal expert systems intended to enhance access to the legal system. Working in platforms that do not require technical expertise, students are able to build apps that incorporate rules-based logic, factor balancing, and mathematical operations to implement the reasoning of a regulatory regime. In this essay, we suggest that teaching students to design apps furthers pedagogic goals associated with the traditional law school curriculum and clinical teaching. In designing legal expert systems, students are required to engage in careful legal analysis and anticipate the problems and questions a typical user will have. Students also need to learn to communicate legal concepts and categories in precise and plain language. Contrary to the traditional law school curriculum, however, which emphasizes case-by-case analysis, in clinics that focus on building legal expert systems, students learn to develop systemic solutions to legal problems. By exposing students to principle of systems design, these classes prepare them for the emerging challenges of 21st century practice.