During February 2026, Dumitru worked on the apollographql/apollo-mcp-server repository, focusing on improving data validation for GraphQL numeric inputs. Using Rust and leveraging skills in API development and GraphQL, Dumitru updated the JSON schema type mapping so that GraphQL Int and Float types now correspond to 'integer' and 'number' respectively. This adjustment addressed issues caused by invalid values sent from the ChatGPT client, preventing server errors and enhancing compatibility. The solution preserved existing validation workflows and required no public API changes, resulting in more robust data ingestion and increased reliability for downstream services dependent on the MCP server.