Langhoff began her career as an investment banker before moving to film production at Revolution Studios, where she began as an assistant in 2001 and became an executive during her seven years of working there. At Revolution Studios, she co-produced the 2007 film Perfect Stranger. When the company closed in 2007, she returned to New Orleans to work in the local independent film industry. She then partnered with filmmakers Jay and Mark Duplass, whom she had known as a teenager, at their production company, Duplass Brothers Productions. She was an associate Producer of their 2011 film Jeff, Who Lives at Home and the Producer of their 2012 film The Do-Deca-Pentathlon. She also produced Safety Not Guaranteed (2012), which starred Mark Duplass. She was appointed President of Duplass Brothers Productions in 2012. In 2014, Langhoff produced The Skeleton Twins, a comedy-drama film starring Kristen Wiig and Bill Hader as estranged fraternal twins. She also produced the film The Bronze (2015) and the HBO series Togetherness created by Jay and Mark Duplass in 2015. Due to her ongoing work with the Duplass brothers, Langhoff has been referred to as "the honorary Duplass sister".
In 2015, Langhoff was awarded the Sundance Institute Red Crown Producer's Award, which is given to a Producer for their "bold vision and a commitment to continuing work as a creative Producer in the independent space". She was also named as one of The Independent magazine's "10 Filmmakers to Watch in 2015".
