Reiner attend the University of Illinois at Urbana.  He earned a BS in Theoretical and Applied Mechanics and BS in Applied Mathematics in 2006.  Reiner would attain a MS in Applied and Computational Mathematics from The Johns Hopkins University in 2009. 
Reiner was a Physicist at the Johns Hopkins University Applied Physics Laboratory from 2006-2013.  During the early 2010s, he got into Bitcoin mining but later realized the potential for developing Bitcoin Applications.  After, Reiner became the Founder and CEO of Armory Technologies.  There, he developed the Armory Bitcoin Client, an alternative wallet application focused on security for heavily-invested Bitcoin users and businesses.  It was the first Bitcoin wallet application to make “Cold Storage” (offline wallets) accessible through an intuitive user interface.  Since March 2016, Reiner has been a Senior Software Engineer at IronNet Cybersecurity.