Fredrik Sterner began his esports career in 2015, competing in CS:GO. At the start of his journey, he played for several mix teams but didn't secure any victories in the tournaments he participated in. Therefore, the player, known by the nickname REZ, undoubtedly accepted an offer from Cringe Gods in early 2016. As it turned out, this decision was the right one. Shortly after, the team was signed by Epsilon eSports, under whose banner Fredrik won his first trophy, a gold medal at ESPORTSM 2016.
After that, Sterner became a champion at Pro Gamer League 2016 - Summer, World Cyber Arena 2016 World Finals, and also secured 3rd-4th place at the Gfinity CS:GO Invitational.
In the summer of 2017, the esports player joined Ninjas in Pyjamas, where he has remained ever since. In his new team, he has repeatedly earned various awards. Some of his most notable achievements include gold medals at Intel Extreme Masters XII - Oakland, Esports Championship Series Season 7 - Europe, Regional Major Rankings 2021: Europe, Intel Extreme Masters XVI - Fall: Europe, and a 1st-2nd place finish at Intel Extreme Masters Dallas 2023: European Open Qualifier #2.
Additionally, with the "Ninjas", Fredrik “REZ” Sterner has earned bronze medals at Regional Major Rankings: Rio Major 2020 - Europe, PGL Major Antwerp 2022: European RMR B, and also silver at Intel Extreme Masters Road to Rio 2022: European RMR A, Copenhagen Gaming Week 2024 ESL Challenger at DreamHack Summer 2024: European Qualifier. Among his personal achievements, he was recognized as the Most Valuable Player at the IEM Season XII - Oakland, held in Oakland in 2017.
Since January 2025, REZ has joined GamerLegion.