ConfigDB is a unified app config system designed to address the pain points of previous configuration systems at Plaid. The system aims to provide availability, runtime update propagation, and programmatic edits while meeting constraints such as high read load, dataset size limits, and data model requirements. ConfigDB stores data in a Git repository hosted on GitHub Enterprise, utilizes protobuf for schema definition and data serialization, and features a transactional read API with type-safe access to datasets. The system also includes validation and approvals mechanisms to ensure data integrity and security. By leveraging existing technologies like S3 and gRPC, ConfigDB provides a scalable and maintainable solution for managing application configurations.