Oleksander Kostyliev entered the CS:GO scene in 2013. His first team was LAN DODGERS, but the cyber athlete did not achieve significant success there. Afterward, he played for Courage Gaming, Hashtag, and Amazing Gaming, where he also struggled to perform at his best. Nevertheless, in September 2014, he caught the attention of the HellRaisers team, with which Oleksander finished in 5th-8th place at the DreamHack Winter 2014 tournament.
In 2015, s1mple moved to FlipSid3 Tactics, but within a few months, he again failed to secure any notable victories. Consequently, he decided to leave the team and even considered suspending his esports career. However, his break was not prolonged. Shortly thereafter, Oleksander joined Team Liquid. In this new team, he emerged as one of the leaders, and his performance significantly contributed to the team's advancement to the finals of ESL One: Cologne 2016.
His impressive performances with Liquid attracted the attention of Natus Vincere (NaVi), where he joined at the end of summer 2016. With NaVi, Kostyliev won the CS:GO Asia Championships 2018, earned silver at the FACEIT Major: London 2018, and claimed gold medals at StarSeries & i-League CSSeason 7, Intel Extreme Masters XIV - World Championship, BLAST Premier: Global Final 2020, Intel Extreme Masters XVI - Cologne, PGL Major Stockholm 2021, and BLAST Premier: World Final 2021. Additionally, the team secured the title of Season 3 champions in the Intel Grand Slam, taking home the grand prize of $1 million.
s1mple is a highly experienced and respected CS player, as evidenced by his numerous personal achievements. He has been recognized 19 times as the MVP of major competitions. Furthermore, he earned the title of best player according to HLTV in both 2018 and 2021.
Oleksander has also set several world records. He holds the record for the most MVP awards, surpassing Nikolaj Ridz, and has been named the Most Valuable Player of the year a record number of times. In 2021 alone, he was recognized as MVP eight times. The Ukrainian esports athlete also holds a record for the most eliminations in a single map. During the IEM Cologne 2021, he eliminated all players of the opposing team four times in the first map of the match between NaVi and G2 Esports.
In 2023, after a disappointing series with NaVi, Oleksander Kostyliev decided to leave the team and took a short break. In March 2024, he joined the Falcons team. Unfortunately, with this new squad, he has not achieved any notable victories, with the only significant result being a 9th-16th place finish at the BLAST Premier: Spring Showdown 2024 tournament.