Castelion Corporation is looking for an experienced ISSM to manage and maintain the Classified Networks out of our Torrance location. The ideal candidate will be a dedicated security professional with a demonstrated ability to work independently and as a member of a team in a fast-paced, high-tech environment. The ISSM's primary function serves as a principal expert and manager on all matters, technical and otherwise, involving the security of information systems under his/her purview. Primary support will be working within Special Access Programs (SAPs) supporting Department of Defense (DoD) agencies, such as HQ Air Force, NAVY, Army, DARPA, etc. The position will provide "day-to-day" support, oversight, and maintenance for Collateral, Sensitive Compartmented Information (SCI) and Special Access Program (SAP) activities. As the site ISSM you will own the end-to-end Information Assurance Program for all classified and controlled information systems at our Torrance facility. You will partner with Program Management, Engineering, IT, Security, and the Cognizant Security Agency (DCSA/SAPCO) to obtain and sustain ATO on schedule, mentor a growing ISSO team, and keep our environment audit ready every day.