Tesfai has appeared in Wicked Wicked Games (2006), Melrose Place (2009) and Franklin & Bash. She is also the founder of jewelry company Fortuned Culture, of which the proceeds go to charity. Following her turn on Jane the Virgin, Tesfai has appeared on Silicon Valley, Rosewood and Superstore. In 2019, Tesfai started appearing in a recurring role on CW superhero series Supergirl, as James Olsen's sister, Kelly Olsen. In March 2019, she was promoted to a series regular for Season 5.
Shortly after commencing her run on Supergirl, Tesfai became good friends with co-stars Katie McGrath and Nicole Maines, of which they use the portmanteau hashtag #Nikazie. Tesfai has also gathered an alliance of the black women of the CW, including Vanessa Morgan (Riverdale), Anna Diop (Titans), Lesley-Ann Brandt (Lucifer) and Candice Patton (The Flash), wherein the cast members support each other in the face of the racism in the industry and the world in general.
- Tesfai is Ethiopian on her mother's side
- Tesfai is best friends with Bridget Regan (Sin Rostro), Yael Grobglas (Petra/Anežka Archuletta), Yara Martinez (Luisa Alver) and Andrea Navedo (Xiomara De La Vega)