Senior Software Engineer (SDE3) — Data & Intelligence Platform in Welwyn Garden City

You'll be a core engineer on the data and intelligence layer that connects Tesco's supply chain forecasting outputs to the people and systems that act on them. The platform sits at the intersection of data engineering, applied ML, and developer infrastructure - you'll work across all three, owning problems end to end. This isn't a role where you'll spend your days in a narrow lane. The work is genuinely varied: one week you're designing a data API, the next you're improving retrieval quality in a RAG pipeline, the next you're working with infrastructure to get a service into production. We're looking for someone who finds that energising rather than uncomfortable.

About the role:

• You will be responsible for Data platform - a high-performance service that brings together multiple data sources - analytical, caching, vector, and object stores - behind a clean typed API. Supply chain data is high-volume and time-sensitive; getting the data layer right underpins everything else the platform does.
• Intelligence layer - we work closely with forecasting teams across the business who produce demand signals, predictions, and recommendations. Our job is to make that intelligence accessible, actionable, and explainable - surfacing it through well-designed APIs, keeping it fresh, and ensuring the right data reaches the right place at the right time.
• LLM integration - a conversational and tool-calling layer that gives supply chain teams natural language access to platform data and forecasts. You'll work on retrieval quality, tool design, prompt architecture, and streaming response pipelines. This is a relatively new area for us and there's genuine room to shape how it evolves.

You will need:

• Takes ownership. When something is broken or missing, you fix it, you don't wait to be asked.
• Is comfortable with ambiguity. Not every problem will have a clear spec, you can navigate that without needing handholding.
• Writes code other engineers want to work with - readable, tested, and with the complexity in the right places.
• Has worked across backend services and data systems in production, and has the scars to show for it.
• Can pick up new technology without being precious about what they already know.

Technically, you're strong in TypeScript and Python (or willingness to learn quickly), you've built or operated data-intensive backend services, and you have some experience with LLM APIs or retrieval systems - enough to be productive quickly, even if you haven't done it at scale before. Kubernetes and cloud-native deployment experience is useful. So is supply chain or forecasting domain knowledge. Neither is required.

The work is meaningful. The platform influences ordering decisions across thousands of stores. When it works well, products are on shelf. When it doesn't, they aren't. That directness of impact is something most engineering roles don't offer.

Nice to have:

• Experience contributing to shared frontend/backend or developer platform infrastructure.
• Infrastructure as code — Helm, Kubernetes manifests, CI/CD pipeline design.
• Supply chain, replenishment, or demand forecasting domain familiarity.

What's in it for you? We’re all about the little helps. That’s why we make sure our Tesco colleague benefits package takes care of you – both in and out of work. Annual bonus scheme of up to 20% of base salary. Holiday starting at 25 days plus a personal day (plus Bank holidays). Private medical insurance. 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, we also offer 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.

About Us: You might know us as a supermarket, technology company or even for our award-winning mobile network. Truth is, we’re all of those things, and much more. Our colleagues work with one goal in mind, helping to make every day a little better for our customers, colleagues and communities all over the world. No two customers are the same, neither are our colleagues. At Tesco, we champion a balance that lets you thrive both in and out of work. Spend 60% of your week collaborating with colleagues at our office locations or local sites and the rest remotely. Whether you're just kicking off your career, juggling passions, or navigating big life events, we're here to support you. We always welcome a conversation about flexible working, so talk to us throughout your application about how we can support. We're proud to be an accredited Disability Confident Leader, where everyone’s welcome. That’s why we commit to providing a fully inclusive and accessible recruitment process. If you need support with your application, click here for more information. And if you're interested in joining our team but don't tick every box, don't let that hold you back from applying.