This is a rare opportunity to take ownership of cyber security architecture at national scale, sitting at the heart of a programme with real national significance. Backed by substantial government investment, our client is developing a world‑first resilient infrastructure capability designed to protect the critical services that modern society depends on, including telecommunications, banking, transport and emergency response. As Principal Security Architect, you will serve as Security Pillar Lead across a portfolio of complex programmes, shaping strategy, leading assurance, and ensuring that the technology underpinning essential national services is built to remain secure and robust under any conditions.