Staff Software Engineer – Experimentation (Hybrid, United Kingdom) Marks & Spencer is seeking a Staff Software Engineer to lead the evolution of our Experimentation platform. You will design, build, and evolve backend-heavy capabilities for experimentation, including APIs, services, automation pipelines, and developer tooling. You will set the technical direction for the platform and champion a self-service model that reduces toil and dependencies. You will partner with product, engineering, and content teams to understand needs and future demand, and mentor engineers to develop strong technical judgment and platform thinking. You will demonstrate a production-first mindset, focusing on observability, resilience, and safe change, and you will produce clear, high-quality documentation for APIs, systems, standards, and operational processes. The ideal candidate has deep backend engineering experience with Java/Kotlin, experience running distributed systems in production, strong Azure cloud experience building scalable, reliable services, and familiarity with experimentation solutions (Optimizely is a plus). You should also have hands-on experience with GraphQL—schema design, federation, evolution, and API governance—and working knowledge of TypeScript and React in API, tooling, or integration contexts. This is a hybrid role in the United Kingdom.

Staff Software Engineer – Experimentation (Hybrid, United Kingdom) Marks & Spencer is seeking a Staff Software Engineer to lead the evolution of our Experimentation platform. You will design, build, and evolve backend-heavy capabilities for experimentation, including APIs, services, automation pipelines, and developer tooling. You will set the technical direction for the platform and champion a self-service model that reduces toil and dependencies. You will partner with product, engineering, and content teams to understand needs and future demand, and mentor engineers to develop strong technical judgment and platform thinking. You will demonstrate a production-first mindset, focusing on observability, resilience, and safe change, and you will produce clear, high-quality documentation for APIs, systems, standards, and operational processes. The ideal candidate has deep backend engineering experience with Java/Kotlin, experience running distributed systems in production, strong Azure cloud experience building scalable, reliable services, and familiarity with experimentation solutions (Optimizely is a plus). You should also have hands-on experience with GraphQL—schema design, federation, evolution, and API governance—and working knowledge of TypeScript and React in API, tooling, or integration contexts. This is a hybrid role in the United Kingdom.