We are seeking an experienced Principal Electrical (ECandI) Commissioning Engineer to support a major defence project at a secure, highly regulated site near Reading. This is a principal role with management responsibility; site-based role requiring a high level of technical expertise, leadership, and experience in commissioning, testing, and assurance of electrical and control systems within safety-critical environments. Role: Senior/Principal Electrical (ECandI) Commissioning Engineer Location: Reading (site-based) Salary: £85,000+ (Based on year''s experience) Key Responsibilities Lead and oversee the commissioning, testing, and validation of electrical and ECandI systems on a complex defence project and provide technical leadership and mentorship to junior commissioning engineers and site teams. Develop, review, and approve commissioning strategies, test procedures, and method statements, alongside supervising functional testing, fault finding, and troubleshooting of complex electrical and control systems. Ensure all commissioning activities comply with project requirements, CDM regulations, and site safety procedures. Produce and review high-quality technical reports, test records, and handover documentation and lead technical reviews, progress meetings, and commissioning coordination sessions. Support the resolution of technical issues, non-conformances, and commissioning shortfalls while acting as a key technical interface between commissioning, design, constructi