Introducing sub-issues: Enhancing issue management on GitHub

GitHub introduces sub-issues, a feature that enables hierarchical task management by breaking larger issues into smaller, trackable child issues.

• •Sub-issues use a parent-child relationship model stored in MySQL, with a separate roll-up table for performant progress tracking without full traversal
• •Data is exposed via GraphQL endpoints, enabling efficient querying and integration with the new Issues list-view components built in React
• •The team dogfooded sub-issues internally throughout development, which surfaced UX improvements like adding issue numbers and repository names to the sub-issue list
• •Beta tester feedback shaped filtering syntax, resulting in filters like has:sub-issues-progress and has:parent-issue
• •Sub-issues support cross-repository work and are compatible with GitHub Enterprise Server and Enterprise Cloud with data residency