Modernizing a Million Lines of Code: Jira's Journey To GraphQL and Relay

Session description

Abstract Discover how we transformed Jira's issue view to GraphQL and Relay—handling billions of monthly interactions across 100+ field types while meeting enterprise compliance and reliability agreements. With hundreds of developers and teams modifying a decade-old codebase daily in a frontend monorepo, we faced unique challenges in technical design and execution. We'll share: - GraphQL schema design for scale - Bridging Redux, Sweet State, and Relay in a multi-team environment - Incremental rollout strategies with feature flags for safe migration - Field-by-field adoption approaches maintaining workflow and compliance - Performance optimization under enterprise-scale load - Testing approaches at scale - Developer experience takeaways Impact & Takeaways - Performance metrics during incremental migration - Developer experience improvements - Cross-team collaboration - Production-proven strategies for state management in existing codebase This isn't about building new—it's about modernizing Jira's critical interface while maintaining compliance for enterprise customers. Ideal for leaders coordinating teams and architects planning GraphQL adoption in regulated organizations.