Daniel Schiffner specializes in security risk assessment and protective design for sports and public assembly venues, airports, embassies, courthouses, and commercial buildings. His work at Thornton Tomasetti includes threat, vulnerability, and risk assessments (TVRAs) and structural design for holistic protective measures such as blast assessments, perimeter security planning, vehicle mitigation strategies, and structural and facade hardening for facilities facing complex security challenges. Daniel has supported the planning and design of transportation hubs, government facilities, and major sports venues, helping owners and project teams integrate protective design measures and achieve SAFETY Act compliance while maintaining operational and user experience goals.