About the Role We are seeking a highly skilled and experienced Senior Security Engineer to join our engineering / service team. You will play a key role in the installation, commissioning, and maintenance of advanced security systems across commercial and residential sites in London and the surrounding region. Your expertise will help ensure that all installed systems operate reliably, meet regulatory and industry standards, and provide a high level of service to clients. Key Responsibilities * Lead the installation of security systems, including CCTV, access control, door entry, and intruder alarms. * Commission and test newly installed systems; ensure correct configuration and integration. * Provide maintenance and service support: carry out planned preventative maintenance (PPM), fault-finding, repairs, upgrades, and reactive maintenance visits. * Participate in an on-call rota for emergency call-outs, troubleshooting, and system restoration. * Conduct site surveys, prepare quotations, and scope new projects. * Produce technical documentation: wiring diagrams, as-fit drawings, commissioning certificates, and handover documentation. * Train end-users / clients in system use and functionality. * Maintain van stock, tools, and spare parts inventory; manage materials efficiently. * Ensure all work complies with relevant Britis...