Syncing changes

This post details the construction and upload of deltas for syncing offline changes made in Trello's mobile applications. It describes the delta structure, which includes entries for model changes and individual field modifications (deltas), and explains how an annotation-based calculator on Android automatically computes these differences. The post also outlines the process of uploading these deltas to the server in the order they were created to maintain data hierarchy, converting them into generalized HTTP POST requests.