He attended Harvard University with co-founder Mark Zuckerberg and others on the founding team. He worked at Facebook from February 2004 to September 2007. Initially, he worked on Wirehog, a file sharing program, together with Adam D'Angelo. McCollum returned to Harvard College, and graduated in 2007 with a Bachelor's degree in Computer Science and went on to get a master's degree in education from the Harvard Graduate School of Education. McCollum was a member of the Harvard team that competed in the 31st Association for Computing Machinery International Collegiate Programming Contest in Tokyo, having placed second in the regional competitions behind Massachusetts Institute of Technology.
On November 20, 2014, Andrew McCollum was announced as new Philo CEO, succeeding Christopher Thorpe.