Lester has been brought on to connect the dots across We Are Pi's strategy product and will work closely with founder and chief executive, Alex Bennett-Grant.
He is leaving his role as executive strategy director at R/GA New York, which he only held for 10 months. Before that, he was group strategy director.
Following his departure, R/GA New York added three strategy leaders to its New York team last week. Felicia Zhang replaces Lester as executive strategy director, joining R/GA from 360i where she was vice-president of strategy.
Esther Ahn joined as group strategy director and Rachael Stets as strategy director.
Discussing Lester's new appointment, R/GA's founder Bennett-Grant said: “It takes a special kind of strategist to navigate the winds of change blowing through ad land while keeping it relevant enough to inspire much needed radical creative solutions. Which is why I'm excited to welcome Mark onto the pirate ship, to further strengthen our strategy product and keep building a refreshingly modern alternative agency in Pi.”