The krogan largely represent the hardened warriors on CDN.  With a lifespan that can be measured in centuries and a millenial stigma from their titular Rebellions, the krogan were neutered by the Genophage for over 1400 years.  Having been given a second chance by Commander Shepard in the light of the Reaper War, the krogan are now experiencing a new Golden Age - though whether this relative peace holds or is merely a pretense for a second galactic war with Tuchanka is still hotly debated.

Please see the krogan retrospectives for more information on what happened between the end of Mass Effect 3 and the "current day."