  The Serenity-S1 is a Xilinx Virtex Ultrascale+ based Advanced
Telecommunications Computing Architecture (ATCA) processing blade that has been
optimised for production. It incorporates many developments from the Serenity-A
and Serenity-Z prototype cards and, where possible, adopts solutions being used
across CERN. It also uses many new parts because commonly used parts have
disappeared from the market during the semiconductor crisis, with only some
returning.
  Improvements to simplify manufacture, the performance of new components, some
of the more difficult aspects of procurement, the performance of
production-grade Samtec 25\,Gb/s optical firefly parts, and issues with the
rack cooling infrastructure are discussed.
