Executive Moves

Amanda Brownfield, most recently president of Geospark Analytics, took the helm of the company as CEO and succeeded Omar Balkissoon, who now holds the positions of executive chairman and a strategic adviser at the Herndon, Virginia-based geospatial data analytics company.

Shaun Bierweiler, formerly president of government solutions business at Cloudera (NYSE: CLDR), has joined information technology firm Riverbed Technology as senior vice president of public sector, GovCon Wire has learned.

Gordon Foster, chief financial officer of Constellis over the past two years, has been appointed a senior vice president and CFO at Serco Inc. – the British contractor's Americas division – in a move that takes effect Oct. 26. He will succeed the Gary Shankman, who is due to retire from the Herndon, Virginia-based contractor by the end of the year.

Jay Smilyk, a more than two-decade industry professional and former eastern regional director of sales at Vectra Networks, has joined Rockville, Maryland-based hardware visibility technology maker Sepio Systems as chief revenue officer.

Michael Lee, former vice president for NASA enterprise information technology services at ManTech International (Nasdaq: MANT), has assumed the position of VP and division manager for the company's portfolio of economic and research agencies.

Diane Nguyen, a more than 25-year financial and accounting leader in the GovCon industry, has joined Microsoft (Nasdaq: MSFT) as chief financial officer of the company’s federal business, GovCon Wire has learned.

Melissa Houghton, former vice president of business development at Redhorse Corp., has been appointed VP of corporate growth at the San Diego, California-based technology services company.

Scott Baum, a former Department of Defense official, has joined Elbit Systems’ (Nasdaq: ESLT) U.S. subsidiary as vice president of strategy and growth, Inside Defense reported Wednesday.

Sarjoo Shah, former chief information officer of Oklahoma’s Department of Health and Human Services, has joined Science Applications International Corp. (NYSE: SAIC) as head of its state and local health information technology programs.

Xavier Williams, a 30-year veteran of AT&T (NYSE: T) and two-time Wash100 Award recipient, will lead American Virtual Cloud Technologies (Nasdaq: AVCT) as CEO starting Oct. 1. He will succeed Darrell Mays, who has been appointed executive vice chairman of the AVCT's board of directors, and will also serve as a board member, the Atlanta-based information technology services provider said Wednesday.