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# Staff Software Engineer - Experimentation

- **Company:** Marks and Spencer plc (UK)
- **Location:** UK
- **Salary:** £48,247.0
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Microsoft Azure, Programming Tools, Distributed Systems, TypeScript, ReactJS, Backend, Kotlin, Graphql
- **Published:** October 22, 2026
- **Apply:** https://www.adzuna.co.uk/jobs/details/5936493874

## About the Role

* 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.
 * 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.

## Description

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.