Sanni worked on the ardatan/graphql-tools repository, delivering deterministic mock generation for the GraphQL mock store to improve test reliability and reproducibility. By introducing API options that allow users to select between random and deterministic values for mock data, Sanni addressed test flakiness and enhanced CI stability. The implementation involved TypeScript and GraphQL, with a focus on mocking strategies and robust test coverage, including deterministic String scalars. Sanni also updated documentation and prepared release artifacts to support adoption. The work demonstrated depth in both technical execution and developer experience, contributing a foundational feature to the GraphQL tooling stack within one month.