The SERENITY Carrier Card has been developed to handle the huge data rates required for high-luminosity operation of CMS at the LHC as part of the Phase-2 upgrade programme. CMS is developing completely new back-end electronics to handle higher bandwidth interfaces to the front-end electronics within CMS and to process the resulting increased data volume (i.e. for delivery for DAQ or to extract a trigger signal). To place the scale of the upgrade in perspective it is useful to consider the tracker readout, which will require an increase in bandwidth from 15 Tbit/s to 184 Tbit/s. SERENITY is a general purpose board compatible with most sub-detectors being developed for the phase-2 upgrade.