[3] In 1998 he began his career as co-driver to Tomasz Kuchar on Polish national events enjoying some good results.
Szczepaniak competed with Kuchar until 2003 on many rounds in Poland and around the globe on the WRC and European Rally Championship calendars.
From 2007 to 2013 he was crewmate to Michał Kościuszko, entering rounds in the World Rally Championship and Poland in a variety of cars including a season in JWRC in 2009, SWRC in 2010, and PWRC in 2011.
Szczepaniak would continue in WRC2 with youngster Hubert Ptaszek for the rest of the season despite sustaining an injury on the Rallye de Portugal.
A full season together in 2019 brought them second place in their WRC2 championship titles including one win at Rally Turkey.