Scharf joins from Red Cell Response, where she held an equivalent role until the end of last year. In her new job, she will run the department with Rapier's existing planning director, Max Wright.
Scharf began her career in 1987, as a planner at IMP in Detroit. After spells at DMB&B and JWT in the US, she moved to the UK, joining JWT London, where she became the European planning director on Mazda. Stints at WWAV Rapp Collins' data strategy unit Zalpha, TBWA\ GGT and Red Cell Response followed.
Scharf will report to Rapier's managing director, Alison Meredith, who said: "It is still rare to find people with Jo's background, but an appreciation of the whole communications mix is vital to Rapier."