Worked on enhancing the data model for attachments in the GetStream/stream-chat-go repository by introducing a MimeType field to the Attachment struct. This addition enables MIME-type aware handling of attachments, allowing the backend to process and render various file formats more accurately. The implementation focused on aligning the data model with its JSON representation, ensuring correct parsing and display of attachment formats throughout the application. Utilizing Go for backend and API development, the work laid the foundation for future type-based validation and features, improving both storage and UI rendering of attachments without introducing any bug fixes during the development period.