Staff Software Engineer - Experimentation

Staff Software Engineer – Experimentation team 

We’re looking for a Staff Software Engineer to play a pivotal role in evolving M&S’s Experimentation platform. This team provides the experimentation capabilities that empower teams across the business to identify savings and drive revenue. Your customers are product teams, engineers, content teams – everyone who works on customer-facing functionality – and your mission is to enable them to run more experiments, more easily and confidently, by creating a robust experimentation platform. 

This is a role for an engineer who is excited by platform thinking, enablement at scale, and revolutionising how experimentation capabilities are modelled, delivered, and accessed across a large organisation. 

Due to high interest, this role may close earlier than advertised. We recommend applying as soon as possible.

What you’ll do 

Your key accountabilities will include: 

• Design, build, and evolve backend‑heavy platform capabilities for experimentation, including APIs, services, automation pipelines, and developer tooling. 
• Set technical direction for the Experimentation platform, influencing architecture and standards beyond your team. 
• Champion a self‑service platform model, building tools, scripts, and automation (including emerging agentic AI use cases) that reduce toil and dependencies. 
• Partner closely with product, engineering, and content teams to understand needs, pain points, and future demand. 
• Mentor engineers at all levels, helping develop strong technical judgement, platform thinking, and engineering craft. 
• Demonstrate a production‑first mindset: observability, resilience, and safe change are core design concerns. 
• Produce clear, high‑quality documentation for APIs, systems, standards, and operational processes. 

Who You Are 

• A strong platform mindset: you build capabilities and tools that power many teams, not just individual features. 
• Deep backend engineering experience with Java/Kotlin, including designing and running distributed systems in production. 
• Strong experience on the Azure cloud platform, building and operating scalable, reliable services. 
• Solid understanding of experimentation solutions (Optimizely experience is a strong plus). 
• Hands‑on experience with GraphQL — schema design, federation, evolution, and API governance (must have). 
• Working knowledge of TypeScript and React, particularly in API, tooling, or integration contexts.  

What’s in it for you? 

Working at M&S means being part of something bigger - helping to deliver quality, value and service to millions of customers every day. We’re inclusive, fast-moving and always evolving, with a strong sense of purpose and a focus on doing the right thing.

Here are just a few of the benefits that make working here even more rewarding:

• 20% colleague discount on all M&S products and many third-party brands for you and someone in your household, available once you’ve completed your probation
• Competitive holiday allowance with the option to buy more
• Strong pension and life assurance to help plan for the future
• Tailored induction and training to support your development from day one
• Exclusive perks and savings through our M&S Choices portal
• Market-leading family policies, including parental, adoption and neonatal leave
• 24/7 wellbeing support, including virtual GP access and mental health services
• One paid volunteer day a year to support a cause that matters to you

Everyone’s Welcome 

We are ambitious about the future of retail. We’re disrupting, innovating, and leading the industry into a more conscientious, inspiring digital era. We’re transforming how we work together and offering our most exciting opportunities yet. Marks & Spencer strives to be an inclusive organisation, trusted and admired by our colleagues, customers, and suppliers. 

We are committed to building diverse and representative teams, where everyone can bring their whole selves to work and be at their best. We support each other and win together. 

If you’d benefit from any support or reasonable adjustments during any stage of the recruitment process, please let us know when completing your application. 

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