Principal Engineer - Technical Lead (Gen AI and MACH Architecture)

Senior Principal Engineer (Tech Lead) to design, build and ship enterprise-grade systems across MACH architectures and production Generative AI. You will spend 65-70% on hands-on delivery and 30-35% on technical leadership, architecture and team guidance. Lead the technical direction of complex client programmes across MACH and production Generative AI, spanning design-to-code workflows, API contracts, cloud infrastructure, deployment and ongoing operation. Own architecture decisions, write and review production code, and mentor engineers while remaining accountable for what ships. Requires minimum three years' Generative AI production experience with at least one AI capability delivered in an enterprise environment, plus deep knowledge of retrieval pipelines, evaluation, cost governance and operational reliability at scale. Experience with Design Systems and Design to Code, and hands-on work with tools such as Figma, Cursor, Claude and Vercel AI SDK. Familiarity with cloud providers (GCP, Vertex AI, AWS Bedrock, Azure OpenAI) and MACH landscape; strong focus on scalability, observability, security and governance. Hybrid work in London (Farringdon) with collaboration across global studios and partners; role involves both production engineering and architecture across frontend and backend domains, including REST/GraphQL APIs, microservices, and containerised deployments. AKQA/WPP Open environment emphasizes production-grade delivery and continuous improvement.