[4] During his studies, Banaszak worked as legislative assistant to Dirk Behrendt at the State Parliament of Berlin.

From 2014 to 2017, he managed the Düsseldorf offices of Members of the European Parliament Terry Reintke and Sven Giegold.

[6] From 2018 to 2022, Banaszak served as co-chair of the Green Party in North Rhine-Westphalia, alongside Mona Neubaur.

[10] In addition to his committee assignments, Banaszak has been a member of the German delegation to the Franco-German Parliamentary Assembly since 2022.

[11] In the negotiations to form a coalition government of the Christian Democratic Union (CDU) and the Green Party under Minister-President of North Rhine-Westphalia Hendrik Wüst following the 2022 state elections, Banaszak and Sven Giegold led their party's delegation in the working group on finances;[12] their counterparts from the CDU were Lutz Lienenkämper and Günter Krings.