Senior Backend Engineer (Python)

We're looking for an experienced Senior Backend Engineer (Python) to build reliable backend services and APIs for search quality tooling within a client delivery team.

🎯 Role impact

You’ll work on Search initiatives for a large multinational retail organization operating across the UK, Ireland, Europe, and Asia. You’ll build tools that help Search teams identify problems, test changes, and measure relevance more efficiently, collaborating with AI, data, DevOps, and Search engineers.

🎯 Responsibilities

• Design and build Python backend services and APIs for search quality tooling, including tools for collecting human relevance judgments
• Review and refactor an existing offline evaluation tool so it can be deployed and run on demand within a CI/CD pipeline
• Translate product requirements into well-structured, maintainable, test-driven code
• Integrate services with shared data platforms, client APIs, and search infrastructure
• Support AI- and LLM-enabled features alongside AI engineers, including automated checks for accuracy and reliability
• Collaborate with product, design, data science, and Search colleagues to turn prototypes into production releases
• Support production systems, resolve incidents, and document technical decisions and trade-offs

🛠️ How you’ll work

• Share work early through documentation, demonstrations, and incremental pull requests
• Own deliverables within agreed architecture and engineering practices
• Communicate decisions, risks, and trade-offs clearly
• Work closely with Search and data science colleagues to understand how tools are used
• Experiment quickly, test assumptions against real data, and iterate based on evidence
• Balance exploration with delivery and avoid unnecessary complexity in early solutions
• Design for reliability, clarity, and adoption by the people who use the tools
• Make sensible trade-offs to deliver usable value early while building solutions that can evolve

🛠️ Requirements

• 6+ years of professional experience in backend or software engineering
• Strong Python skills, including experience building maintainable production services and REST APIs
• Experience reviewing, refactoring, and productionizing existing code for reliable pipeline execution
• Strong testing discipline across application and data components, including test-driven development
• Understanding of clean design principles such as SOLID
• Experience with CI/CD, version control, and containerization, ideally including on-demand or temporary environments
• Experience with a major cloud platform, ideally Microsoft Azure
• Understanding of security, scalability, and observability for production services
• Proficiency with both SQL and NoSQL databases
• Experience integrating services with data pipelines, APIs, and existing applications
• Exposure to integrating LLM-based or other AI features into backend services, including validation of model outputs
• Proven ability to deliver iterative, user-focused solutions with appropriate attention to reliability and security
• Strong written and verbal communication skills
• A collaborative approach to multidisciplinary product delivery

➕ Nice to have

• Experience in retail or ecommerce search, or with Elasticsearch or another production search platform
• Familiarity with offline evaluation, A/B testing, or ranking metrics such as nDCG
• Experience with event streaming, such as Kafka, or medallion-style data pipelines
• Experience building internal tools for rating or annotation

🤗 Benefits

• Competitive compensation package
• Medical insurance