Are you an experienced PKI Engineer ready to take greater ownership of complex, secure infrastructure?Sopra Steria is delivering a unique solution from the ground up for the Defence sector, integrating infrastructure and applications within highly secure, mission-critical environments.This is an opportunity to play a leading role in shaping PKI services for a nationally significant programme, influencing design decisions, strengthening governance, and ensuring secure certificate services operate at scale.In this role, you will act as a senior technical specialist for PKI, providing engineering leadership across certificate management, certificate template design, HSM administration, PKI governance, and lifecycle processes.You will work closely with architecture, infrastructure, application, security, Windows, Linux, and web teams to define PKI requirements, guide implementation, and ensure solutions meet operational, security, and compliance needs.Please note this role requires the person to be on site full time in our office. What you will be doing:Lead PKI engineering and operational activities across secure enterprise environments.Own the design, review, deployment, and governance of certificate templates.Provide senior technical guidance on certificate management across Windows, Linux, web-based platforms, enterprise applications, and infrastructure services.Work with architects, engineers, security teams, and application owners to define PKI integration requirements and