Mr. Sieff is a former Staff Assistant to the United States House of Representatives, Office of Minority Leader, Washington, D.C.; Law Intern to Honorable Winslow Christian, Justice of the California Court of Appeal; Staff Assistant, Department of Justice, San Francisco, California; and  private corporate counsel and counselor at  law in Los Angeles, California .  Mr. Sieff became licensed as a Real Estate Broker in California in 1980.

Community affiliations have included the Santa Monica Bar Association (Past President),   Rotary Club of Santa Monica (Past Director),  Santa Monica Junior Chamber of Commerce (Past President), Santa Monica Chamber of Commerce (Past Director), American Red Cross (Past local director), Boys and Girls Club (Council Member), and numerous children's sports leagues.