Dirk Westervelt has enjoyed repeat collaborations with several filmmakers throughout his career. After working for a time in the camera department, Westervelt moved to the cutting room on the first two features directed by F. Gary Grey (the hit comedy Friday and action/drama Set It Off) as assistant editor and then associate editor. 

For George Tillman Jr., he began as associate editor on the director's hit comedy/drama Soul Food, then served as editor on the biographical drama Men of Honor, the action/drama Faster, and on Notorious (about the life of the rapper known as Notorious B.I.G.). He served as visual effects editor and temp music editor on Guillermo del Toro's superhero fantasy Hellboy and on his action/thriller Blade II. 

For writer-director Rick Famuyiwa, he began as additional editor on the coming-of-age tale The Wood and went on to edit Famuyiwa's romantic comedies Brown Sugar and Our Family Wedding, as well as the political thriller Confirmation (for HBO Films). Westervelt also worked as editor on the 3D fantasy adventure Journey to the Center of the Earth, directed by Eric Brevig. In 2014, he edited Jaume Collet-Serra's action/thriller Run All Night, starring Liam Neeson.