Cloud & Hosting - Principal Platform Engineer – DevSecOps / DevEx

Business Introduction GSK remains committed to achieving bold commercial ambitions for the future. By 2031, we aim to deliver £40 billion in annual sales, leveraging our existing strong performance momentum to significantly increase our positive impact on the health of billions of patients globally. Our Ahead Together strategy is centred on early intervention to prevent and alter the course of disease, thereby protecting people and supporting healthcare systems. Our diverse portfolio consists of vaccines, specialty medicines, and general medicines. Through continuous innovation and a dedicated focus on scientific and technical excellence, we strive to develop and launch new, groundbreaking treatments that address critical health challenges. Job Purpose  The Principal Platform Engineer – DevSecOps/DevEx builds and runs Modern Engineering platforms as automated, secure, self-service infrastructure, sets the engineering standard within that platform, mentors the engineers around them, and treats the teams who consume the platform as customers. The role works through infrastructure-as-code and golden paths rather than manual configuration, uses AI-assisted engineering across code generation, review and testing, and engineers reliability in by defining SLOs, instrumenting for observability and automating away toil. Modern Engineering Platforms enable the D&T organisation to build, deploy, and operate applications faster, more securely, and more reliably by embedding modern DevSecOps and SRE practices. This is the senior hands-on engineering role in the platform team, insourced at the grades covered by this description while engineering at G7b and below is delivered through managed service partners, so the role integrates and assures partner components as well as building. Engineering roadmap and direction sit with the Engineering Director, reference architecture and standards sit with the Platform Architect, backlog order sits with the Product Owner, and deep reliability engineering sits with the Site Reliability Engineer deployed from Reliability Engineering & Operations. Key Responsibilities •        Design, build and automate platform infrastructure using infrastructure-as-code and golden paths, so that provisioning is repeatable rather than reconstructed each time. •        Use AI-assisted engineering across code generation, review and testing to accelerate delivery and raise quality, reviewing AI-generated output before it is merged. •        Build self-service capabilities and paved roads that reduce friction for consuming teams, so adoption does not depend on the platform team's availability. •        Engineer for reliability by defining SLOs, instrumenting platforms for observability and automating to reduce toil, working with the Site Reliability Engineer on standards. •        Set and uphold engineering standards, secure-by-default practices and code quality within the platform, and hold them in code review. •        Contribute to incident response and drive permanent automated fixes with Reliability Engineering rather than repeating manual recovery. •        Mentor and technically lead other engineers, including partner engineers, linking engineering work to platform OKRs and outcomes. •        Integrate and assure supplier or managed-service components, holding partner-delivered engineering to the same standards and code quality as internal work. •        Work the platform's manual task and toil backlog, converting identified candidates into automation and evidencing the effort removed. •        Close observability coverage gaps for the platform, so that reliability can be measured rather than inferred. •        Contribute engineering-led items to the platform backlog held by the Product Owner, including technical debt