Joseph M. Hellerstein is an American professor of computer science at the University of California, Berkeley, where he works on database systems and computer networks. He co-founded Trifacta with Jeffrey Heer and Sean Kandel in 2012, which stemmed from their research project, Wrangler.

Trifacta is a privately owned software company headquartered in San Francisco with offices in Bangalore, Boston, Berlin and London. The company was founded in October 2012 and primarily develops data wrangling software for data exploration and self-service data preparation on cloud and on-premises data platforms.