Worked on the graphql-hive/gateway repository to enhance the stability of batch processing in GraphQL query execution. Addressed a critical bug in DataLoader by ensuring that sparse batch results were transformed into dense arrays, padding missing entries with null values to prevent execution-time errors. This targeted fix improved the reliability of the batch resolution path, reducing downstream failures and runtime exceptions. The work was implemented using JavaScript and TypeScript, with a focus on robust testing practices. By refining the DataLoader’s handling of batch results, the changes contributed to more dependable gateway performance without introducing broad or disruptive modifications.