Brandon Watson, head of developer experiences for Windows Phone, is leaving Microsoft for a position at Amazon, where he'll be the Director of the Kindle Cross Platform team. Watson was one of the most visible figures in Microsoft's developer out reach program, well known for taking to social media to directly engage with developers and consumers.

Mary Jo-Foley, writing on the ZDNet blog, confirmed earlier rumours about the departure and noted that Microsoft has not yet appointed a replacement for Watson.

In his role Watson has acted as a developer evangelist for the platform, speaking at events like Nokia World, but also representing the developer voice within Microsoft. But, within the Windows Phone developer community, he was best know for directly interacting with developers through email, Twitter and other direct channels. This level of human contact proved to be very popular with developers, one of whom described him as "the man to contact if you want something done".

While the departure is high profile, he leaves behind a team that has very much embraced the open to developers philosophy that Wastson espoused. Maintaining that attitude, by appointing the right successor, will be important as Microsoft looks to grow the size and quality of the Windows Phone Marketplace and develop the next generation of platform developer tools, documentation and related activities.