Gertler is credited with leading the campaign for Mendes’ debut single “Life Of The Party”, which sold over 148,000 copies in its first week and has since been certified Gold by the RIAA. The single made Mendes the youngest ever artist to break into the Billboard Hot 100’s Top 25 with a debut single. Gertler also is credited with developing the campaign behind Shawn’s first studio album Handwritten which topped the Billboard 200 at number one, making Mendes, at the age of 16, the youngest artist to do so since Justin Bieber released his album My World 2.0 in 2010.

After graduating from Homewood-Flossmoor High School, Gertler began his career in music as a 19-year-old intern at Atlantic Records. He then went on to work in Warner Music Group’s direct-to-consumer division while also managing hip-hop artist and fellow H-F Alumni, Rockie Fresh. In 2012, Gertler signed Rockie Fresh to Rick Ross’s Maybach Music Group / Atlantic Records imprint.

In 2014, Gertler discovered Shawn Mendes online and subsequently became his manager after flying him out to New York to record & meet with Island Records. With Shawn Mendes & Rockie Fresh as clients, he founded the management company AG Artists (Andrew Gertler Artists, LLC).