Keast launched his career in New York City, quickly followed by international demand as a guest conductor. He regularly appears at venues including Amsterdam’s Concertgebouw, Munich’s Gasteig, the Opéra National de Paris, the Staatsoper Hamburg, Theater an der Wien, Hamburg’s Elbphilharmonie, and the Festspielhaus Baden-Baden. Described as drawing out “refined and concentrated playing” with “assured sensitivity” (Financial Times), Keast has conducted performances with orchestras such as the Tonkünstler Orchester Vienna, NDR Elbphilharmonieorchester, MDR Sinfonieorchester, Rundfunk-Sinfonieorchester Berlin, and the Belgian National Orchestra.