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Principal Software Engineer - Loyalty

Location(s) London Job ID 40560 Closing Date 28/02/2023 13:01 Contract Full time Hours 40 Contract Type Permanent Salary and Benefits Competitive

Advance the world of digital through M&S

Leading the transformation of an industry. The continuous pursuit of new information, resourcefulness and invention. Thousands, if not millions of people benefiting from your product-led ideas, every day. That’s why you join M&S Tech. Here, you’ll be proud of your projects, enhance your understanding of new technologies, and shape the future of a new, digitally prevailing brand of retail. Progress isn’t in the pipeline, it’s already happening. And we’re as determined to advance technology through M&S, as we are to advance M&S through technology. Want to help us?

It’s a mindset, a special drive and an enthusiasm that says, ‘We can’t wait to solve this problem’. It’s growing closer as a team through deep discussions about the technologies we love, whether next-gen or old classics. Most of all, it’s wanting to share that excitement with our customers and colleagues – reinventing retail into its most innovative form, then unlocking fresh potential and raising the bar yet again.

Explore M&S Tech



Our salaries are competitive and reviewed every year.

Colleague Discount

Receive 20% discount in-store and online for you and a partner or family member.


Competitive holiday entitlement

Holiday Buy

You can reduce your salary in exchange for up to one contractual week of additional holiday, subject to eligibility and National Living Wage requirements.


We have discretionary bonus schemes depending on the role that you do and the performance of our business.


If you save 3% of your pay into our Pension Saving Plan we will add an extra 6%. More details at

Life Assurance

Free cover of two times your annual salary up to age 70. If you pay into our Pension Saving Plan we double this to four times.


Allows you to save between £5 and £500 per month for three years with the option to buy shares at a 20% discount – or simply take your savings back.


Invest between £10 and £150 each month from your gross salary to buy M&S shares and build up an investment.

My Choices

Enjoy savings on everyday costs to holidays, recognise your colleague’s success and get more information and support on your wellbeing & benefits.

Cycle to Work

Hire a bike and accessories through Cycle to Work and save on tax and national insurance.


Buy the latest technology with interest free financing directly from your salary.

Health & Wellbeing

Save money on you and your families medical and dental expenses. Get great discounts on gym memberships, active wear, and health products.

Mental Health Support

Free 24/7 support from our expert health and wellbeing partners PAM Wellbeing - including free counselling and CBT as well as support for your family.

Giving Back

Support charities you care about the most by donating through your pay or even volunteer for them for one day.

Financial Wellbeing

Access to information and support to help you manage your finances from long term savings to managing your debt or money worries.

Celebration Time

Celebration time provides additional time off (up to one day per year) for a special occasion.

Virtual GP service

Free and unlimited access to a qualified GP for all UK colleagues and their families.

Principal Software Engineer - Loyalty

Job purpose

As part of the M&S Software Engineering team, you’ll be joining a well-loved historic brand, working on solutions that serves millions of loyal customers and thousands of colleagues! With ethical values that run right through the company’s core and technology leaders that truly understand software engineers and engineering, it’s an exciting time as we’re redefining ourselves into a digital first and engineering-led organisation, with the quality of our engineering team being a key differentiator.

We are seeking a passionate Principal Software Engineer who will provide technical expertise, ship thoughtfully and operate with excellence. Being creative, curious, and adventurous, you will be an integral part of our empowered, self-managing, multi-disciplinary engineering teams - crafting, building, releasing, and maintaining products. Working as an equal partner with the Product and Delivery teams you will deliver sophisticated and robust solutions to solve daring problems for our customers and colleagues.

You will play a key role in driving our ambition to build an outstanding software engineering team, environment, and culture. We are looking for people to join our community of engineers to drive this transformation, build a modern digital ecosystem using exciting technologies and do the best work of their careers.

Reports to

Head of Software Engineering

M&S peers

Principal Software Engineering Managers, Head of Product, Senior Technical Programme Managers

Scope of the role

Principal Engineer for the Loyalty Product Group

Loyalty platform(Sparks) at M&S is one of the leading loyalty programmes in Retail Industry. We want to enable customer retention and ensure customer feels rewarded with our exciting offers and proposition.

Role of Principal Engineer is to enable to scale and build outstanding loyalty platform, to enable us to personalise customer offers across omnichannel. They will be responsible for crafting and leading technical excellence for multiple products (Domains, API’s and Micro Frontends).

The tech stack is Java, Python, React, Kafka, Azure, etc).

Key Accountabilities & Responsibilities

The Principal Software Engineer role is the embodiment of ‘solving problems through technology’ with key responsibilities as follows:

  • Lead technical excellence from design to operations and launch of core product features or strategic programmes
  • Drive technical direction and influence our overall strategy advising decisions on both Technology and Product investments as well as teams’ setup
  • Champion Communities of Practice to help establish engineering excellence at M&S
  • Lead by example via contributions to our engineering ecosystem
  • Pioneer and promote methodologies like clean code and clean architecture
  • Advocate for engineering productivity, delivery quality and operational excellence through a continuous ecosystem
  • Drive DevOps practices to automate the Product development life cycle and ownership demeanour
  • Partner with both Engineering, Technology and Product leadership to ensure strategies align
  • Develop the best and mentor other senior engineering roles across the entire landscape
  • Promote effective innovation across all of engineering
  • Advocate and strategize for continuous industrialisation and product-minded tech capabilities
  • Inspire ideas to foster purpose and mastery to engineering teams, leading them towards autonomy and maturity
  • Amplify engineering teams by efficiently unblocking them with direction, leading upward, and establishing alignment
  • Raise the profile of MS Tech through public content and contribution/creation into open-source technology
  • Support recruitment, onboarding and internal and external brand outreach activities
Key Experience – the ideal candidate will have


  • Significant track record of strategic and innovative thinking, as well as execution and implementation
  • Experience in implementing solutions using modern software architectures (Domain Driven Design, hexagonal, CQRS), data and streaming architectures (e.g.: Kappa/lambda).
  • Specialist in clean code and implementation of design patterns for common problems.
  • Depth of knowledge in Information Security, you can design, quality review and quality assure solutions and services with security controls embedded, specifically engineered as mitigation against security threats as a core part of the solutions and services
  • Confident driving system design conversations, you can design systems characterised by high levels of risk, impact, and business or technical complexity
  • Able to analyse current processes, identify, and implement opportunities to optimise processes, and lead and develop a team of specialists to deliver service improvements
  • Experience of using a variety of methods of prototyping. You know how to share methodologies and can mentor others. You look at strategic service design end to end
  • Strong ability to influence industry-based models for the development of new technology applications. You develop effective implementation and procurement strategies, consistent with business needs. You ensure alignment to relevant technical strategies, policies, standards, and practices
  • Strong understanding of quality assurance, testing quadrants and the testing pyramid, and how to apply them
  • Ability to lead senior engineers and technical customers to a desired outcome, without prescribing it
  • Authoritative skills at cloud computing (network, security, serverless, Kubernetes etc) and automation
  • Experience with implementation of Observability and Reliability using market technologies (e.g.: New Relic)
  • Good experience with Performance Engineering (load testing, derivations, tuning, core web vitals, page speed etc.)
  • Expertise in reliability testing
  • Able to influence people at senior levels and from the highly technical to non-technical
  • Previous polyglot hands-on senior software engineer
  • Leading large product areas with 10+ teams
  • Previous software engineering community leadership experience
  • Professional presentation delivery at internal and external events
  • An ambition to be an open-source contributor, technology writer or speaker
  • Experience in event driven API architectures and associated best practises
  • Advocate and experience of Continuous Integration and Continuous Delivery
  • Advanced experience of DevOps: you build it, you run it
  • Advanced experience with cloud engineering
  • Cares about the business and the bigger picture with significant prior examples
  • Excellent interpersonal skills, both written and spoken and able to adjust for different audiences
  • A senior leadership mentality that is willing to take ownership
  • Demonstrable entrepreneurship in previous organisation(s)
Works closely with

You’ll be working closely with other Principal Software Engineers, Heads of Software Engineering, Heads of Product, Commercial, Finance, CTOs, Principal Software Engineering Managers, Software Engineering Managers, Software Engineers, and Product Managers to collaboratively address problems. There will be day-to-day interactions with Technical Programme Managers, who you’ll work with to constantly evolve your team’s ways of working. Depending on your team(s), you could also interact with other specialists such as Architects, Data Scientists, UX/UI Designers, and analytics authorities.

As a member of M&S Software Engineering, you’ll also have the opportunity to work with and learn from other engineers and specialists in the organisation through Business Platforms, Product Portfolios, Product Groups, other teams and Communities of Practice.

M&S is ready to push boundaries to lead the industry into a greener, speedier, more inspiring digital era. That’s why we’re revolutionising how we work and offering our most exciting opportunities yet. There’s never been a better time to be part of our team. Marks & Spencer aims to be an inclusive organisation, trusted and admired by our colleagues, customers and suppliers. Join us and make an immediate impact. We are committed to an active Inclusion, Diversity and Equal Opportunities Policy, which starts with our recruitment and selection process, and we are happy to talk flexible working.  We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process. If you consider yourself to have a disability or learning difficulty which means you are unable to complete the application process online, please get in touch either by phone on 0345 300 3725 or by email so we can make alternative arrangements for you.


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