1. Club career
Janek Sternberg has had a dynamic club career, making his way through various German clubs and also experiencing a spell in Hungary. His journey includes initial development, professional debut, and subsequent transfers across different leagues.
1.1. Werder Bremen
Sternberg joined Werder Bremen in 2013, having transferred from Hamburger SV. Initially, he played matches for Werder's reserve team. He made his first-team debut in a Bundesliga match against SC Paderborn 07 on 29 November 2014. He played the entire match, which ended in a 4-0 home victory for Werder Bremen.
1.2. Ferencváros
On 21 January 2017, Sternberg made a move to Hungarian football, joining Ferencváros. During his time with the club, he competed in the Nemzeti Bajnokság I, the top-tier league in Hungary.
1.3. 1. FC Kaiserslautern
In May 2018, it was announced that Sternberg would join 1. FC Kaiserslautern for the 2018-19 season. This transfer came at a time when the club had just been relegated to the 3. Liga. Sternberg signed a contract with 1. FC Kaiserslautern that was set to last until 2021.
1.4. Hallescher FC
On 31 January 2020, Sternberg transferred to Hallescher FC. He signed a deal with the club that extended until the summer of 2021.
1.5. VfB Lübeck
As a free agent, Sternberg joined VfB Lübeck in January 2023. At the time of his transfer, VfB Lübeck was in first place in the Regionalliga Nord. He signed a one-year contract with the club, which included an option for an additional year.
2. International career
Janek Sternberg has represented his home country, Germany, at the youth international level. He is a youth international player for Germany at the U18 level.