Developed backend support for Class Collections Management in the asuc-octo/berkeleytime repository, enabling users to create, rename, and delete class collections while attaching personal notes. Leveraged TypeScript, GraphQL, and MongoDB to implement a robust API, finalizing the collection module with atomic operations to prevent race conditions and type-safe resolver mappings for reliability. Introduced note-length validation to ensure data integrity and addressed critical backend issues by refining queries, mutations, and handling edge cases such as non-existent classes. Prepared the backend for seamless Apollo GraphQL frontend integration, ultimately streamlining study planning and collaboration by reducing manual data curation for users.