Guillen was appointed to the SDHC Board of Commissioners by Mayor Jerry Sanders in 2009.

Known for his expertise in sales planning, market penetration and asset disposition, Guillen oversees all sales and business development functions – including price opinions, account management, contract negotiations, and property management. Guillen also directs a network of realtors and real estate practitioners located throughout Imperial, Orange, Riverside, and San Diego counties. In addition, he actively participates in assisting first-time home buyers.

Guillen has also held positions with Mesa Realty, Coldwell Banker, NRT, Inc. and New Century Homes & Investments, Inc. Guillen obtained his California real estate license in 1993 and a brokers license in 2006.