Worked on the nestjs/nest repository to address a specific issue in file upload validation by improving error messaging when a file buffer is missing. Focused on backend development using TypeScript, the contribution enhanced the file type validator’s feedback, making it easier for developers to identify and resolve upload issues. The solution incorporated unit testing to ensure reliability and maintainability of the core validation logic. By providing a clear and traceable commit, the work supported better debugging and streamlined issue triage for the NestJS community. This targeted bug fix contributed to ongoing efforts to strengthen validation reliability within the project’s core library.