Primary location:
HELSINKIShape the architecture and engineering quality of business-critical tools used across 1,000+ stores in Finland.
We are looking for a Principal Engineer to develop and evolve digital services for the retail store environment within S Group. You’ll help build reliable, secure, and scalable solutions that enable smooth and efficient operations in retail business. The primary workplace is our Helsinki office, where we meet our colleagues regularly. When your duties allow, you can also work flexibly remotely for part of the week.
About the job
Your expertise will support two product operating domains:
Employee Experience (EX) which develops and operates tools and processes for S Group’s retail store employees in Prisma hypermarkets, S-markets, and in our convenience stores Sale and Alepa.
Leadership & Learning Experience (LX) where the focus group is store management and store leadership through data, analytics, operation models and continuous learning.
In essence through this position, you’ll make a meaningful impact in the daily work of store employees and leaders.
As a Principal Engineer, you will be part of discovery and delivery of digital services used in store environments and for ensuring that built solutions are high-quality, secure, and aligned with S Group’s architectural and information security principles. You can take overall technical ownership including hands-on work of demanding application development where no ready-made models exist. Our solutions are built using modern development practices and cloud technologies.
Principal engineer guides technical decision-making, mentors' others, and acts in close collaboration with stakeholders. The position offers significant autonomy and responsibility, with direct impact on production stability, information security, business goals, and end user satisfaction.
You will work alongside the Tech Lead for the EX and LX areas, with ownership of technical architecture across your scope. You’ll collaborate closely with experts from business, design, and technology in cross-functional teams and squads. In your job as a Principal Engineer, you enable the success of product squads by providing your seniority and willingness to help. We champion customer-centricity, team autonomy, and decision-making led by expertise, data and customer insight.
What are we looking for?
We are looking for a highly experienced product-minded development professional with a strong technical background and typically 10+ years of relevant experience. You have experience to work independently, take broad technical ownership, and mentor other engineers.
You are comfortable working in early problem‑space exploration together with analysts, designers and business stakeholders. You help frame problems, explore solution options, and assess feasibility before implementation decisions are made.
Success in the role requires strong analytical and problem-solving skills, the ability to manage complex technical systems, and deep expertise in application implementation, code quality, and maintainability. Engineering collaboration skills are essential, as quality is ensured through peer reviews and shared responsibility. Eagerness to work and drive AI-assisted development is required in this role as is also the willingness to understand business and customer insight. In this role, fluent communication skills in English are required. Communicative Finnish is expected, enabling you to follow and take part in relevant discussions.
We expect experience from a modern technology stack such as AWS, React, Node.js and Kotlin but more importantly in this role you are expected to evaluate and make technology selections which are relevant for our area of responsibility and expertise.
As product mindset is crucial in success in this role, we expect that you consider engineering as product discipline, not only as solution delivery practise.
What we offer to you
In this role, you’ll build digital services that are used daily in store environments – solutions which have impact on business operations and employee experience thus enabling better customer experience. As a Principal Engineer, you will have broad technical ownership and autonomy in complex, business-critical solutions, shaping architecture and long-term technical direction. The position combines hands-on development with technical leadership in a stable yet modern environment where your expertise truly matters. We value active participation in the interest of continuous improvement of our ways of working and strong product thinking.
Also:
At S Group, we are committed to fostering a diverse and non-discriminatory working environment where the unique backgrounds, skills, and perspectives of all our employees are respected and valued.
Interested? We’ll be happy to hear from you!
Please send us your CV and an application highlighting your related skills by 26.5.2026 at the latest. We will actively review applications and invite the most suitable candidates for further discussion. We will notify all applicants about moving forward within two weeks after the deadline.
If you have any questions, please contact the Hiring Manager of the position, Head of IT StoreOps Mikko Lehtoniemi by email mikko.lehtoniemi@sok.fi.
Our interview process is both respectful and comprehensive. You’ll meet our recruiter, hiring manager and some teammates. We’ll discuss technical things as well as softer skills, validating your technical expertise, and performing a suitability assessment. The aim is to ensure we can offer you what you are looking for and to make sure you’re the right person for the job. Despite the outcome, we strive to make the process a positive one.
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