Before taking the acquisitions job, he was chief financial officer of MSN and served as a board member of the MSNBC joint venture.

Jaffe joined Microsoft in 1995 as a member of the corporate strategy group, responsible for supplying economic analysis and strategy for various Microsoft business units. In 1999, Microsoft formed a corporate development office, and Jaffe joined that division.

In corporate development, Jaffe held various positions and in 2000 became the general manager of Microsoft corporate development, with responsibilities for managing Microsoft's investments, corporate alliances and acquisitions in the consumer related divisions, including MSN, MSNBC, WebTV, Xbox, Microsoft Games, Microsoft's digital-media initiatives and other consumer-related activities.

Jaffe oversaw, executed and/or managed numerous transactions and alliances while in corporate development. These activities included acquisitions and investments spanning small, medium, and large-sized organizations, as well as Microsoft's major investments in cable and telecom companies. While in corporate development, Jaffe held several board and board advisory positions on behalf of Microsoft.