Senior Full-Stack Developer, K Group

K-ryhmä; Helsinki; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Culture & sport benefit

Employee benefits (shopping, stores)

Occupational health care

Leisure time accident insurance

Office in Kalasatama, Helsinki

Job summary

K Group’s BHI eCom team seeks an experienced senior full-stack developer to help build the Cyclone platform powering eCom in Finland, Sweden and Norway. You will contribute to the backlog, review peers, and help define the architectural direction while coordinating with stakeholders and supporting the product owner.

The role emphasizes strong frontend (TypeScript/React) and backend (Node.js) skills, secure coding, testing, and opportunities to mentor teammates.

Qualifications

• 5+ years of hands-on software product development experience.
• Strong fundamentals in programming and computer science.
• Solid knowledge of microservices architectures.
• Frontend expertise with TypeScript and React, plus HTML/CSS.
• Experience in designing secure, scalable services and APIs with Node.js.
• Strong SQL skills and ability to optimize queries.
• Experience with unit, integration, and end-to-end testing.
• Hands-on experience integrating generative AI into products or workflows.
• Knowledge of secure coding practices (OWASP Top 10).
• Ability to lead, collaborate and mentor within a team.

Responsibilities

• Contribute to the team backlog and deliver features in a multi-deployment environment.
• Review others' code, lead by example, and improve engineering practices.
• Architecturally steer and align technical direction with stakeholders.
• Balance collaboration with independent work to deliver value.

Skills

5+ years exp

OO fundamentals

Microservices

TypeScript/React

Node.js

SQL

Testing (Mocha/Jest)

AI integration

OWASP Top 10

Team leadership

Education

Engineering degree or equivalent experience

Tools

Docker

GitHub Actions

Kafka

PostgreSQL

Mocha

Jest

Webpack

Job description

K Group's BHI (Building and Home Improvement) eCom team is looking for an experienced full-stack developer. Are you looking for a change of scenery, or want to explore new challenges on developing a larger system with multiple deployments? And if delivering business value, technical debt management and agile methodologies sound like good ideas, this could be your next career move.

The BHI eCom Team

The team’s mission is to develop the Cyclone platform powering the eCom solutions for K-Rauta, Byggmakker and K-Bygg. We have developed our own eCom platform, called Cyclone, serving our Building and Home Improvement businesses in Finland, Sweden and Norway with many different ERPs in the back end, a part of our larger Building and Technical Trade business. The Cyclone dev team is a distributed and multinational agile software development team. We are fulfilling business needs by developing front-ends and microservice capabilities integrating with the back-ends. We subscribe to a DevOps-philosophy – everyone is empowered to not just implement features, but also to improve and support the platform.

Your Role as a Senior Developer

As a senior full-stack developer in the team you will be contributing to the team’s backlog. You don’t just develop your own code, but also review code from other team members, lead by example and help the team strengthen engineering practices by coaching and mentoring other developers. You have a central role in architectural planning and building and leading the technical direction in the team. You also coordinate with the rest of the team and our stakeholders and support your team’s product owner in maintaining and refining the backlog.

What We Are Looking for

• 5+ years of hands‑on software product development experience
• Strong understanding of core programming concepts and computer science fundamentals
• Solid knowledge of microservices architectures
• Proficiency in TypeScript, React and modern frontend technologies (HTML, CSS, browser APIs). You write clean, maintainable and accessible code following best practices
• Experience in designing and building secure and scalable services and APIs with Node.js
• Solid SQL fundamentals; you are able to design schemas and write efficient, performant queries
• Knowledge of unit, integration and end‑to‑end testing and building validation strategies
• Hands‑on experience of integrating generative AI into products or development workflows
• Practical experience in secure coding practices and mitigating common risks (e.g. OWASP Top 10)
• Passion and vision to contribute to our common platform, demonstrating technical leadership and making our team better as a whole
• An ability to work collaboratively, as well as independently, as part of a team
• Fluent communication in English, which is our working language
• A degree in engineering, major in information technology, software- or web development – or equivalent experience
• You can make it to Kalasatama in Helsinki once a week to be with the team on‑site
• You will need the existing right to work in Finland. K Group is unable to sponsor work permits or visas

Our Tech Stack

HTML – SCSS – TypeScript – React – Redux – Node.js – REST APIs – Single Page Apps – Docker – GitHub Actions – Kafka – PostgreSQL – Mocha – Jest – Webpack

What We Can Offer You

The K Group offers attractive opportunities for driving the trading sector forward. You’ll be working in a key function of a leading sector company and innovate solutions for its core operations in the grocery trade, building and technical trade, and car trade.

This role is worth your attention because you'll get:

• A great multinational team, suitably professional yet not too serious
• A cool and complex micro‑service based omnichannel platform to work with
• The ability to work in a fast‑moving environment where your input really matters
• An open work culture where you bring your own ideas to the table, both technically, and improving our services and ways of working as well
• Extensive employee benefits unique to the K group. These include, among others: Culture & sport benefit (ePassi), shopping benefits that apply in K-Group stores and staff shops, own occupational health care services and leisure time accident insurance
• We also have several benefits offered by our partners, including optical stores, accommodation and travel, as well as sports & wellbeing services
• For office days - modern office with several accommodations (e.g., collaboration and break areas throughout the office, gym, health care services, restaurant and cafeteria…) along good connections in Kalasatama, Helsinki

At K Group, you get to create solutions that make people’s everyday lives easier, with the strength of data gathered from 1.5 million daily customer encounters. You’ll have your finger on the pulse of our consumer and business customers in the grocery trade, building and technical trade and car trade, and get to take part in various interesting projects.

For digital experts with their eye on the future, we offer vast amounts of data and the chance to harness their creativity to improve people’s everyday lives. Our culture encourages reinvention, experimentation, mistakes and learning.

Corporate responsibility is integrated into K Group’s day‑to‑day activities, and we strive to help our customers make good choices. We want to make life easier for our customers by offering them quality products and services that promote welfare. The focus of our responsibility work is on the welfare of both people and the environment.

We at K Group value diversity and believe that different backgrounds and perspectives are key to success. We strive to create a work environment where everyone has the opportunity to grow. Equality, non‑discrimination, and fairness are our core principles in recruitment, compensation, and career development.