Kanban customizable columns, “under the hood”

This post details the technical implementation of the 'Kanban customizable columns' feature in Azure DevOps. It introduces 'WIT Extensions' as a mechanism to dynamically attach fields and rules to work items at runtime, without altering work item type definitions. Specifically, it describes the 'Kanban Column' WIT Extension, which synchronizes the work item's state with its position on a Kanban board. The post explains the predicate logic for attaching/detaching WIT Extensions based on backlog membership and area path, and illustrates how a work item can appear on multiple boards if teams share an area path, detailing the rule execution flow in such scenarios. It also notes current limitations of WIT Extensions, such as lack of query and reporting integration, with a future goal of customer-defined extensions and more componentized process definitions.