Senior Backend Developer

Senior Backend Developer We offer a dynamic, collaborative, friendly and growth-oriented work environment. We strive to make you reach your goals fast! Opportunities for quick career advancement and vigorous learning. Apply now, Join Kolomolo! We usually respond within a day 🚀 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 development opportunities in a growing tech company; Continuous learning culture: mentorship, internal training, and certifications; Flexible, agile work environment (hybrid in Kraków); Office perks: great coffee, tea, fresh fruit, snacks, and a fun atmosphere; Flat management structure, where your voice matters; Regular team events and a social, supportive work culture; B2B contract or Contract of Mandate (Umowa Zlecenie); 🌟 Why Join Kolomolo? At Kolomolo , we prioritize innovation, agility, and autonomy. Our teams have the freedom to own their work, share ideas, and make meaningful contributions. Inspired by Scandinavian values , we believe in work-life harmony and creating an inclusive culture where everyone thrives. You will be part of a passionate, skilled, and friendly team that works hard and celebrates together. Here, you can build your career on your own terms, with opportunities to grow, learn, and make a real impact. Our Flat Structure & The Culture of Inclusion At Kolomolo, we break the corporate mold. We offer: Agile Teams & Autonomy : No micromanagement. You’ll own your projects and enjoy the freedom to innovate. Work-Life Harmony : Inspired by Scandinavian values, we prioritize balance and flexibility, where remote work and asynchronous collaboration are in our DNA. Learning & Growth : Continuous learning is at our core. We reward hard work, value smart ideas, and foster an environment of mutual respect and trust. Inclusive Culture : We believe in DEI: diversity, equity and inclusion. We are committed to creating an environment where every individual, regardless of background, identity, or experience feels valued, respected, and empowered to thrive. Join Kolomolo and elevate your career with cutting-edge technology, a supportive team, and a company that truly values your input. Ready for the next step? Apply now and start an exciting journey of growth and innovation with us! Remote status Fully Remote About Kolomolo To be leaders in digital modernization by helping companies embrace latest cutting edge technologies to optimize their business with the help of our talented experts. Founded in 2016 Co-workers About 100 Turnover 5M