Principal Software Engineer

Join Us

At Sainsbury’s Tech, you’ll help power one of the UK’s largest and most-loved multi-channel, multi-brand retailers. As a Principal Engineer, you will drive engineering excellence, shape modern technology standards, and influence the future of retail technology for millions of customers.

You’ll work in a supportive, inclusive, and collaborative engineering community—one that values experimentation, innovation, and evidence-based decision making. If you’re passionate about modern engineering practises and want the freedom to explore, lead, and deliver at scale, this is the place to thrive.

What You’ll Do

• Setting and evolving engineering strategy, standards, and best practises across your domain.
• Influencing innovation, modern ways of working, and technical direction across engineering teams.
• Leading by example through deep technical expertise, supporting Staff Engineers and teams to deliver scalable, high‑performance technology solutions.
• Guiding engineers and senior leaders with expert insight on technical risk, impact assessment, and prioritisation.
• Designing and overseeing the delivery of large‑scale, high‑availability systems using cutting‑edge technologies.
• Driving the adoption and continuous improvement of engineering practises, using data and evidence to support decision‑making.
• Leverage AI and intelligent automation to modernise our systems, streamline decision making, and ensure the organisation remains future fit in a rapidly evolving technology landscape.
• Shaping engineering culture by developing talent, mentoring engineers, and contributing to a thriving community of practise.

Essential Criteria

Technical Excellence:

• Deep hands‑on expertise in at least one modern backend language (e.g., Java, .NET, Golang, Node.js, Python, Kotlin).
• Strong understanding of engineering ecosystems, software architectures, and scalable system design.
• Experience leading the development of complex, high‑performance, distributed systems.
• Proven ability to define, evolve, and govern technical standards and engineering best practises.

Leadership & Influence:

• Proven experience in a senior or principal engineering role within a modern technology organisation.
• Proven ability to influence engineering strategy and shape technology direction across multiple teams or domains.
• Experience working with Senior Engineering Managers and technical leaders to guide engineering vision and delivery.

Ways of Working:

• Strong advocate for agile methodologies and modern engineering practises.
• Proven ability to build collaborative, inclusive relationships across engineering communities.
• Comfortable making data‑driven decisions and evaluating trade-offs at scale.

Culture & Mentorship:

• Strong experience developing colleagues, mentoring engineers at all levels, and contributing to engineering culture.
• Passion for innovation, continuous improvement, and enabling others to succeed.

Why Sainsbury’s Tech?

• Influence technology used by millions of customers every day
• Freedom to innovate, experiment, and drive real change
• Supportive engineering community and career‑long development
• Flexible working and strong work‑life balance
• Be part of shaping the future of retail technology

What’s in It for You

• Flexible working with a balanced approach to home and office
• Colleague discounts across Sainsbury’s, Argos and Habitat
• Private health cover
• Generous holiday allowance
• Bonus scheme
• Car allowance
• Pension plan
• Discounts on gyms, restaurants, holidays, retail and more

We’d all like amazing work to do, and real work-life balance. That’s waiting for you at Sainsbury’s. Think about the scale it takes to feed the nation. The level of data, transactions and variety involved. Then you’ll realise this is a modern software engineering environment, because it has to be. We’ve made significant investment in the standards and principles that shape how we work. We iterate, learn, experiment and champion ways of working such as Agile, Scrum and XP. So you can look forward to exciting opportunities across everything from AI to reusable tech. " We are committed to being a truly inclusive retailer, so you’ll be welcomed whoever you are and wherever you work. Around here, there’s always the chance to try something new - whether that’s as part of an evolving team or somewhere else across the business - and we take development seriously and promise to support you. We also recognise and celebrate colleagues when they go the extra mile and, where possible, offer flexible working. When you join our team, we’ll also offer you an amazing range of benefits. Here are some of them: Starting off with colleague discount, you'll be able to get 10% off at Sainsbury's, Argos, TU and Habitat after 4 weeks. This increases to 15% off at Sainsbury’s every Friday and Saturday and 15% off at Argos every pay day. We've also got you covered for your future with our pensions scheme and life cover. You'll also be able to share in our success as you may be eligible for a performance-related bonus of up to 65% of salary, depending on how we perform (in cash and shares). Your wellbeing is important to us too. You'll receive an annual holiday allowance, and you can buy additional holiday. We also offer other benefits that will help your money go further such as season ticket loans, cycle to work scheme, health cash plans, pay advance (where you can access some of your pay before pay day) as well access to a great range of discounts from hundreds of other retailers. You'll also receive a company car cash allowance unless you are going to travel 10,000 business miles in your role, then you'll be able to choose a car. And if you ever need it there is also an employee assistance programme, you will also be eligible for private healthcare too. Moments that matter are as important to us as they are to you which is why we give up to 26 weeks’ pay for maternity or adoption leave and up to 4 weeks’ pay for paternity leave. Please see www.sainsburys.jobs for a range of our benefits (note, length of service and eligibility criteria may apply)."