Senior Software Engineer - Payments & Customer Engagement

Sitoo Kassasystem; Stockholms kommun; On-site; SEK 450,000 - 600,000; Full time

Benefits offered by this job

Inclusive culture

Professional development opportunities

Team activities and celebrations

Job summary

Sitoo Kassasystem in Stockholms län is seeking a Senior Software Engineer. In this role, you will focus on backend development using Node.js, designing and operating scalable cloud services while contributing to frontend tasks when necessary. Join a forward-thinking team that values innovation and inclusivity, working with the latest technologies including AWS, React, and CI/CD practices. This is an opportunity to make a significant impact on the future of retail by improving customer engagement systems.

Qualifications

• Strong experience in backend development with Node.js.
• Solid experience with scalable cloud services.
• Ability to take ownership of production systems.

Responsibilities

• Design, build, and operate backend services focusing on performance.
• Contribute to frontend development for a seamless user experience.
• Improve processes and tooling, write tests, and contribute to CI/CD pipelines.

Skills

Backend development with Node.js

Building and maintaining scalable cloud services

Frontend and backend experience

Understanding of distributed systems

CI/CD practices

Fluent in English

Tools

AWS

React

TypeScript

Docker

Kubernetes

Job description

Join our highly skilled team of developers – breaking new ground and shaping the future of retail.

We dare to dream big, we have the courage to keep raising the bar, and we’re committed to being a force for good in retail - helping both established and fast-growing brands meet the ever-changing expectations of their customers.

Sitoo is a fast-growing technology company exploring how far we can take innovation to deliver the world’s best Unified Commerce Platform and Point of Sale. Our technology is used in more than 20 countries - a number that keeps growing thanks to our incredible team of engineers. And we have no intention of slowing down. Are you the Senior Software Engineer we’re looking for?

Your mission at Sitoo

As a Software Engineer at Sitoo, you’ll join a small, autonomous team building and evolving our next-generation platform. This is a fullstack role but with a strong backend focus, where you’ll work across the stack but spend most of your time designing, building, and improving backend services.

You won’t just write code and hand it over – you take ownership of the full lifecycle: design, development, deployment, operation, and continuous improvement. At the same time, you’ll contribute to frontend applications when needed, ensuring a seamless and high-quality user experience.

A big part of your work will involve making thoughtful technical decisions, improving system architecture, and ensuring that what we build is scalable, reliable, and maintainable over time.

About the team

The Payments & Customer Engagement team develops, maintains, and operates Sitoo’s payment and customer engagement integrations. We connect the POS platform with CRM and loyalty systems to enable seamless customer recognition, personalized interactions, and smarter in-store experiences. By ensuring reliable data flows between systems, we help retailers create more connected customer journeys, strengthen loyalty programs, and deliver a more consistent user‑experience.

What you’ll do

In this role, you will design, build, and operate backend services with a strong focus on performance, scalability, and reliability. While your main focus is backend, you’ll also contribute to frontend development when needed to ensure a seamless user experience.

You’ll take end-to-end ownership of Sitoo’s web products, improving both functionality and technical foundations over time. Working in AWS, you’ll help evolve existing infrastructure and keep a close eye on system health through monitoring, alerts, and observability.

You’ll collaborate closely with your team to improve processes and tooling, write tests to maintain high quality, and contribute to CI/CD pipelines and engineering best practices.

What you’ll work with

• Backend: Node.js (core focus)

• Frontend: React, TypeScript

• Cloud: AWS

• Architectures: APIs, event-driven systems, distributed systems

• Practices: CI/CD, automated testing, Infrastructure as Code

What you bring to the table

• Strong experience in backend development with Node.js

• Solid experience building and maintaining scalable cloud services

• Experience working across the stack (frontend + backend), with a backend-heavy focus

• Good understanding of distributed systems and asynchronous architectures

• Experience with modern CI/CD practices and cloud platforms (AWS, Azure, or GCP)

• Ability to take ownership of systems in production, including monitoring and improving them over time

• A pragmatic, product-oriented mindset with focus on real user value

• Fluent in English, both written and spoken

Bonus points

• Experience with payments solutions

• Experience with AWS services such as SQS, SNS, DynamoDB, Lambda, or Aurora

• Familiarity with Docker or Kubernetes

• Experience with observability and incident handling in production systems

• Familiarity with AI-assisted development tools like GitHub Copilot or Cursor

Why Sitoo

We are forward thinkers. By turning curiosity into knowledge — and knowledge into continuous improvement — we break new ground and shape the future of retail.

We believe in an inclusive culture where everyone feels like they belong. We support each other, win together, celebrate success together, and overcome challenges together.

Today, we are close to 100 dedicated experts with a positive and solution-oriented mindset. Most importantly, we take care of each other — and we never forget to have fun.