Senior Backend Developer

🚀 Senior Backend Developer

Location: Krakow, Poland or Tumba, Sweden (Hybrid)
Contract: B2B, Full-Time

Join the Future of Digital Tech with Kolomolo

At Kolomolo, we don’t just follow trends - we set them. As a global supplier of IT services and digital modernization solutions, we help businesses embrace cutting-edge technology to optimize their operations. Now, we are growing and looking for fresh talent to grow with us.

Are you proactive, tech-savvy, and eager to build your career in IT? This role could be your perfect fit.

About the Role

Are you a backend developer who enjoys solving real-world problems with clean, scalable code? Do you want your work to have a meaningful impact beyond the screen? At Kolomolo,we are looking for a technically driven and collaborative Senior Backend Developer to join our cross-functional team developing our digital platform supporting modern dairy farmers around the world.

In this role, you will work closely with Product Owners, Project Managers, Scrum Masters, UX Designers, QA Engineers, and other developers to build and maintain the backend services powering our website. You will be involved in the entire feature lifecycle - from design and development to testing, deployment, monitoring, and incident handling.

You will build and evolve backend functionality that supports Service Technicians and Installers in their daily work. This includes solutions for installation, configuration, equipment health monitoring, troubleshooting, sw/fw update orchestration, device lifecycle orchestration, and IoT-enabled services. You will help shape robust, secure, scalable, and observable backend services using modern, cloud-native technologies.

This role is ideal for someone who’s excited to deliver reliable systems at scale, enjoys working with data-intensive applications, and is passionate about making a difference in the lives of real users.

 What You’ll Be Doing

• Design, build, and maintain backend services for our platform;

• Collaborate with a cross-functional team to deliver high-quality features end to end;

• Write secure and testable APIs following OWASP and clean code principles;

• Manage infrastructure and deployments using modern IaC and DevOps tools;

• Work on data-heavy services that are central to our platform’s performance and

reliability;

• Monitor services in production, respond to incidents, and continuously improve

system resilience;

• Contribute to our culture of learning and knowledge sharing.

 What We Are Looking For

We are looking for someone with at least 7 years of backend development experience.

You should also have a solid foundation in computer science, with strong knowledge

of algorithms, data structures, and system design.

• Languages & Runtime: JavaScript, TypeScript, Node.js, npm;

• Cloud & Infrastructure: AWS (Lambda, S3, DynamoDB, RDS, VPC), CDK,

Kubernetes, Terraform;

• Architecture & Patterns: REST API development, API security (authentication,

authorization, OWASP best practices), event-driven architecture;

• Testing & Quality: Jest (unit testing), Cypress (E2E), JMeter (load testing),

SonarQube;

• DevOps & Observability: Git, CI/CD pipelines, Docker, Grafana, Loki, Sentry,

OpsGenie;

• Best Practices: Clean code, secure coding, code reviews, production monitoring,

incident response;

• Special Focus: Experience working with data-intensive and high-traffic applications;

• Computer Science Fundamentals: Algorithms, data structures, system design.

You are not just a developer – you are a team player and a problem solver. We believe you will

thrive here if you:

• Take responsibility for your work and follow through;

• Have strong technical curiosity and a drive to continuously learn;

• Are proactive and enjoy taking initiative;

• Value collaboration and helping others succeed;

• Have experience handling incidents and working with customer service to improve

production systems;

• Have worked with production-grade systems and understand the importance of quality, reliability, and supportability;

• Are fluent in English (required) and preferably also in Swedish;

• Are able and willing to work from our Tumba office at least 3 days per week.

What is in It for You

•  Competitive salary and benefits;

•  Career developme