She gained attention in the role of Kayla in the 2018 film Blockers,[3] for which Refinery29 referred to her as "the film's breakout star."[4] Viswanathan went on to star as the lead in the 2019 coming-of-age film Hala, along with co-starring in Bad Education. She co-stars in the TBS comedy anthology, Miracle Workers, and had a recurring role in Janet King.