Nounderline contributed to API and backend development across two repositories, focusing on practical enhancements and integration readiness. In neynarxyz/OAS, they implemented the Notification Tokens API using TypeScript and OpenAPI Specification, introducing a new endpoint for token retrieval with a well-defined response schema and updated versioning to support downstream integrations. For Effect-TS/effect, Nounderline improved the HttpServerResponse API by refining redirect semantics and adding explicit cookie expiration, leveraging Node.js and TypeScript to align with common HTTP practices. Their work emphasized clear API contracts, maintainability, and client compatibility, demonstrating a methodical approach to backend engineering without addressing major bug fixes.