The CMS Computing is based on Grid technologies and is organized in a so called Tier structure, with one Tier-0 at CERN at the location of the experiment, 7 Tier-1 centers and more than 40 Tier-2 centers round the world. DESY is hosting one of the Tier-2 centers, which is operated by the DESY CMS group in close collaboration with the DESY-IT staff and CMS members from the University of Hamburg.

Roughly half of the Tier-2 CPU capacity is used for centrally managed production of Monte Carlo events and reprocessing of data, while the other half can be used by individual users. Part of the storage space is centrally managed by CMS, another substantial part is managed by the local data managers to host data samples of interest for the local and national user community.

To complement the Grid based computing and storage resources DESY hosts the National Analysis Facility (NAF) for the German user community. CMS members from all German CMS institutes are involved to shape the NAF for efficient local data analysis.

DESY is also contributing to the central computing efforts of CMS. The CMS Remote Center at DESY can be used for various central CMS shifts to support data taking and data certification.

Members from the DESY CMS group are in the national NFDI consortium PUNCH4NFDI.