Metni began his professional racing career in 2017, taking part in the Gold class of the IMSA GT3 Cup Challenge for Kelly-Moss Road and Race. Prior to the start of the season, Metni had only participated in track days, and "came to [motorsports] really, really late." He was invited to a track day by a friend, which eventually led to him searching for a full-time drive with Kelly-Moss for 2017. Through 16 races, he claimed a sole class podium finish en route to a sixth-place finish in the championship. At the end of the year, Metni also took part in the 24 Hours of COTA with Brookspeed International Motorsport, taking the SP3 class victory.
