He is best known for his whip cracking stage show which he performs at several Renaissance festivals and posts on social media, where he has over 3 million followers.

Lepiarz earned money as a street performer in Faneuil Hall and Harvard Square, using the personas "Jacques Ze Whipper" (sometimes alternately spelled "Whippeur" to emphasize the exaggerated French accent) and "Jack the Whipper" (both a reference to Jack the Ripper).

[1] Throughout the year, Jack performs at multiple Renaissance fairs throughout the United States, as his persona "Jacques Ze Whipper."

[10][11][12] Jack joined TikTok when a clip of him brandishing a flaming whip at King Richard's Faire went viral on the social media platform.

[7] In 2022, the video also caught the attention of producers for America's Got Talent, and Jack auditioned for the television show.

[18][19] In 2023, Lepiarz participated in a study at Northeastern University, focused on the "extremes of human motor control."