Speaker
Description
European XFEL relies on multiple distributed services to support scientific operations, from proposal management through experiment preparation to data acquisition, analysis, and archiving. Keeping workflows coherent across these systems requires more than metadata exchange: it requires shared definitions, validation rules, and governance for how operational metadata is managed. At European XFEL, this role has increasingly been taken on by myMdC.
This contribution presents the evolution of myMdC from a central metadata catalogue into a facility-wide service supporting a shared operational contract across services. Recent developments include the redesign of proposal-team models and role governance, the extension of permissions and service interfaces, the integration of instrument and technique information, the expansion of dataset- and file-level inventory models, and closer alignment with logbook and archiving workflows. A representative example is the iterative refinement of proposal-team roles, where operational experience repeatedly required adjustments to role semantics, responsibilities, and eligibility checks to keep the contract both consistent and practical across services.
The main focus of this contribution is on lessons learned. Our experience shows that central contracts must evolve incrementally rather than through fixed upfront designs; governance and role semantics are as important as technical schemas; metadata alignment depends not only on APIs, but also on operational ownership, and an appropriate degree of flexibility. Effective governance also requires corresponding UI and workflow changes. These lessons may help other large-scale facilities design sustainable and interoperable metadata architectures in production environments.
