Sosanya has appeared in many roles in the theatre, on television and in films. Her first big break in theatre was in Anthony and Cleopatra at the National Theatre, and with the 2001 series Teachers. She also appeared in Sorted, People Like Us, Love Actually, Nathan Barley, Renaissance, Casanova, as Karen Blaine in the Jonathan Creek episode "The Three Gamblers", Much Ado About Nothing, Cape Wrath/Meadowlands, the Doctor Who episode "Fear Her", and FM.