[4][5][6] She took theatre studies at the National University of Singapore before relocating to the United Kingdom, where she graduated in 2012 with a Master of Arts in Acting from the Royal Welsh College of Music & Drama.

Vasan played a witch in Kenneth Branagh's Macbeth at the Manchester International Festival and for its New York run at the Park Avenue Armory.

In 2018, Vasan played Zahra Alsaadi in the Channel 4 sitcom Hang Ups and had a role in the anthology film London Unplugged.

Vasan joined the main cast of the BBC spy thriller Killing Eve for its fourth and final series as Pam.

She returned to the stage as Stella Kowalski in the London revival of A Streetcar Named Desire opposite Paul Mescal and Patsy Ferran.