Principal Software Engineer - Digital & Payments

Sainsbury's; City Of London; Hybrid; GBP 80,000 - 100,000; Full time

Job summary

A leading UK retailer is seeking a Principal Engineer to drive innovation in the Digital & Payments area. The role will focus on software engineering excellence, fostering collaboration, and leveraging AI for impactful solutions. With a hybrid working model, you will contribute to high-performing teams, tackle critical technology decisions, and shape the future of retail technology.

Benefits

Colleague discount

Holiday allowance

Competitive Bonus scheme

Car allowance

Pension plan

Hybrid working model

Special offers on gym memberships

Qualifications

• Experience across a range of technologies including ReactJS, Java, and Kotlin.
• Proven ability to write clean, maintainable code and share best practices.
• Strong understanding of quality assurance and testing frameworks.
• Ability to analyze and improve processes.
• Strong knowledge of QA and testing frameworks.
• Expertise in cloud computing and automation.

Responsibilities

• Lead technological innovation in software engineering.
• Steer teams through critical technology decisions and challenges.
• Promote AI usage and data analytics to improve retail experiences.
• Lead efforts to utilize AI for efficiency.
• Guide and mentor engineers towards shared outcomes.

Skills

Strategic thinking

Clean code writing

AI tooling experience

System design facilitation

Process analysis and optimization

Mentoring and knowledge sharing

Quality assurance understanding

Cloud computing expertise

Performance engineering commitment

Diverse perspective inclusion

Full-stack technology ability

Tools

New Relic

ReactJS

Next.js

Java

Springboot

Kotlin

Kafka

Job description

Why join us

Joining Sainsbury's Tech means becoming part of an organisation that powers the UK's leading multi-channel, multi-brand retailer. As a Principal Engineer in the Digital & Payments area, you will play a pivotal role in driving innovation and engineering excellence within our dynamic and inclusive environment. You'll have the opportunity to work alongside talented teams building software, enabling engineers to succeed and shaping the direction of technology standards and best practices.

With the freedom to explore, experiment, and lead the way in helping create high performing teams, you'll contribute to building and delivering scalable solutions that impact millions of customers. We offer growth opportunities, a supportive community of practice, and a collaborative culture that values evidence-based decision-making and ownership of outcomes. Join our team and be at the forefront of shaping the future of retail technology while enjoying a work-life balance that allows you to thrive both personally and professionally.

What you'll do

As a principal software engineer you stand at the core of technological innovation, blending deep technical expertise with visionary technical leadership for software engineering. In our fast‑evolving digital and payments environment, this role demands mastery across highly scalable systems, and the latest in secure, customer‑facing technologies both front and back‑end development. Yet technical acumen is just the beginning. The principal engineer inspires and elevates teams through influence—leading by example, fostering collaboration, and championing bold new approaches without relying on formal authority.

Fearless in the face of complexity, you are entrusted to steer teams through critical technology decisions, courageously questioning assumptions and challenging the status quo. The principal is relentless in ensuring that every solution not only pushes boundaries but also aligns with our technical standards and industry best practices, safeguarding quality at every step and understanding value released.

Equally, this leader is a catalyst for continuous improvement, always scanning the horizon for emerging trends. By actively promoting the use of AI and ensuring we have the right analytics, they enable teams to unlock new efficiencies and deliver truly transformative retail experiences. Their guidance ensures our teams do not just keep pace with change but help define the future of digital retail across the Sainsburys & Argos brands.

What you'll need in order to succeed

• A proven ability to think strategically and creatively across multiple teams at extreme scale, and to turn ideas into impactful solutions.
• Commitment to writing clean, maintainable code and sharing best practices in design patterns.
• Experience with AI tooling, understanding how teams can approach the challenge of bringing it into the development process. Being able to explain the ‘why’ and ‘how’ it can be used.
• Skilled at facilitating system design conversations, welcoming input from all team members and valuing diverse perspectives.
• Ability to analyse and optimise processes, leading teams to deliver meaningful development and service improvements.
• Experience with a range of prototyping methods, and a passion for mentoring others and sharing methodologies.
• Strong understanding of quality assurance and testing frameworks, and how to apply them in practice.
• Ability to guide staff & senior engineers and technical stakeholders towards shared outcomes, fostering collaboration rather than prescribing solutions.
• Expertise in cloud computing, automation, and reliability engineering, with a willingness to share knowledge and support others’ growth.
• Experience across monitoring and alerting using technologies such as New Relic, and a commitment to performance engineering.
• Values inclusion actively seeking out different viewpoints and creates an environment where everyone can contribute and thrive.
• We use a variety of technologies across Digital and Payments ReactJS, Next.js, Java, Springboot, Kotlin, Kafka as examples. You should have strong ability across both front and backend technologies, and capable of learning and leading new languages and technologies.

In return you'll get

• Colleague discount across the multi-brands - Sainsbury's, Argos and Habitat
• Holiday allowance
• Competitive Bonus scheme
• Car allowance
• Pension plan
• Hybrid working model
• Special offers on gym memberships, restaurants, holidays, retail vouchers and more

Qualifications

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).

Responsibilities

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 for us to feed the nation. The level of data, transactions and variety it involves. Then you’ll realise that ours is a modern software engineering environment because it has to be. We’ve made serious investment into a Tech Academy and into setting standards and principles. We iterate, learn, experiment and push ways of working such as Agile, Scrum and XP. So you can look forward to awesome opportunities in everything from AI to reusable tech.