An overview of how the Office of the Clerk has used GraphQL to modernize a large legacy system used to manage legislative data and processes in the House of Representatives. The talk will cover architecture, technologies, process and an overview of our application. We have moved significant portions of our application from a legacy database management and application framework to a modern relational database with a microservice business logic layer and a single page application client. GraphQL is used to tie the application, data and business logic together in a single API that is shared across multiple applications and modules. The initial approach has evolved into a platform for building applications that host complex data and business logic. We are also evolving our architecture to deliver data from our applications directly to legislative branch partners over a GraphQL endpoint, replacing multiple legacy delivery methods.