Backstage v1.52.0

This release focuses on enterprise-scale performance and UI modernization. The Catalog backend received substantial PostgreSQL optimizations and a new parallel query architecture that eliminates loading stutters. Significant updates to the Backstage UI library introduce better async data handling and a consolidated semantic color system. Platform engineers should note breaking changes to catalog stitching and frontend discovery logic.

Major Catalog Performance and Responsiveness Overhaul — The catalog list view is now significantly faster and more responsive. By splitting the entity count from the list data and optimizing PostgreSQL queries, the UI loads immediately even in large catalogs, providing a much smoother experience for developers browsing services.

Removal of Immediate Mode Stitching — All catalog stitching is now asynchronous. If you relied on the immediate mode for instant updates after an entity change, you must now account for a brief background processing delay. This change ensures the catalog remains stable and scalable under heavy load.

New Default Frontend Discovery API — The frontend now respects discovery.endpoints configuration. This requires platform engineers to verify their configuration to ensure internal-only URLs are not accidentally exposed to external browsers, which could break frontend-to-backend routing.

Enhanced UI Components and Semantic Theming — The Backstage UI (BUI) now supports advanced asynchronous loading for Select and Combobox components, new semantic color tokens for better theming, and a dedicated NumberField. This enables developers to build more polished, high-performance UI components with less effort.

Dedicated Secrets Schema Support for Scaffolder Actions — Software Templates can now securely handle sensitive data like credentials separately from standard inputs. This allows for more robust automation workflows where passwords or tokens are handled with specific validation and security boundaries.