Software Development Engineer III

The Product & Engineering team is responsible for designing, building and scaling Data & AI products that power intelligent experiences, decisions and actions across the Tesco ecosystem. The role is hybrid, requiring presence at London or Welwyn Garden City offices 3 days a week. The following outline presents the key responsibilities, qualifications, and benefits.

• Software Development Engineer III – senior, hands‑on engineer specialising in building and operating GenAI powered products, including LLM based applications and agentic workflows that enable intelligent decision making and automation.
• Work across the full product lifecycle, translating complex business problems into production‑grade solutions across data, backend services, APIs and user‑facing applications, with focus on reliability, guardrails and real user impact.
• Provide technical leadership by designing shared GenAI capabilities, supporting live systems and raising engineering and AI delivery standards across the team through mentoring and rigorous design practice.
• Take ideas from discovery through rapid prototypes to production‑grade solutions that combine data, user‑facing applications and backend services.
• Work closely with product managers, designers, data science and engineering teams to translate business needs into well‑designed technical solutions.
• Design and deliver LLM based applications and AI agents that enable intelligent decision making and automation, applying pragmatic engineering patterns and appropriate guardrails.
• Design and consume APIs that support responsive, intuitive UIs, working across backend, data and frontend layers to deliver coherent, production‑ready experiences.
• Build shared capabilities (libraries, templates, services, prompts/config patterns, evaluation suites) that reduce duplication and enable other squads to adopt GenAI safely and consistently.
• Support and operate live systems, troubleshoot complex issues, perform root‑cause analysis and continuously improve reliability, quality and speed of delivery.
• Build and maintain web‑based user interfaces using React.js, modern JavaScript/Type Script, HTML and CSS, enabling colleagues to interact effectively with data and AI based tools.
• Promote strong software engineering practices across backend and frontend development, including CI/CD, testing, secure by default development, performance optimisation and observability.
• Provide hands‑on technical leadership through design reviews, mentoring and knowledge sharing.

• Strong experience as a senior software engineer delivering and operating production systems.
• Solid backend engineering experience (e.g., Python or similar), including API design, testing, CI/CD and operational support.
• Practical experience building LLM‑powered applications (e.g., copilots, assistants, agent‑based workflows), with a focus on reliability and real user impact.
• Good working knowledge of React.js and modern JavaScript/Type Script, with experience building and maintaining production web interfaces.
• Proficiency with HTML and CSS, and an understanding of usability, accessibility and performance considerations.
• Experience working across data, backend and UI layers, collaborating with others rather than owning every layer in isolation.
• Ability to make thoughtful technical trade‑offs, communicate clearly with both technical and non‑technical stakeholders and work effectively in a product‑led team.

• Annual bonus scheme of up to 10% of base salary.
• Holiday starting at 25 days plus a personal day (plus Bank holidays).
• 26 weeks maternity and adoption leave (12 months service required at the qualifying date) at full pay, followed by 13 weeks of Statutory Maternity Pay or Statutory Adoption Pay, plus 6 weeks fully paid paternity leave.
• Free 24/7 virtual GP service.
• Employee Assistance Programme (EAP) for you and your family, free access to a range of experts to support your mental wellbeing.

These benefits are a shortened summary; please refer to our policies for full details.