Senior Backend Engineer (Java, Kotlin, Spring Boot, AWS)

Responsibilities

We are looking for a strong backend engineer who wants to design and scale core systems powering product and assortment management across a large retail ecosystem.

You will take ownership of backend architecture and system evolution within the assortment management domain, building scalable services and integrations across a complex, event-driven enterprise landscape. You act as a technical driver within the team, working closely with architects, product owners and stakeholders to deliver robust, high-quality solutions.

Your key responsibilities include:

• Design and develop scalable backend services, APIs and integrations using Kotlin and Spring Boot within distributed systems.
• Translate complex business and product data requirements into robust, maintainable and scalable system designs.
• Lead the design and evolution of event-driven architectures and asynchronous processing using Kafka.
• Design and integrate backend systems within AWS and Kubernetes-based enterprise environments.
• Drive data modeling and persistence strategies using PostgreSQL and cloud-native approaches.
• Act as a technical interface between business, product and engineering teams, leading solution design and backlog refinement.
• Drive engineering best practices, observability, reliability and architectural consistency across the platform.
• Lead troubleshooting, optimization and continuous improvement initiatives while mentoring less experienced engineers.

Benefits

• Motivizer Benefits Platform with a monthly budget of 550 PLN for benefits such as medical care, meal tickets, sports cards, gym memberships, cinema tickets, shop vouchers and discounts.
• Access to a multi-language learning platform for language practice and learning.
• Regular internal and external training opportunities supporting ongoing learning and development.
• Internal community collaboration, including networking events, coding challenges and company parties.

Qualifications

• Completed university degree in Computer Science or a comparable technical field.
• 6+ years of professional experience in backend development using Kotlin and Spring Boot in complex environments.
• Strong expertise in REST APIs, microservices, distributed systems and event-driven architectures.
• Deep hands-on experience with Kafka and asynchronous processing patterns in production systems.
• Strong experience with AWS and Kubernetes, including Amazon EKS, in scalable environments.
• Solid experience with PostgreSQL and designing performant, reliable data models.
• Experience with CI/CD, containerization, observability tooling and modern security concepts, including OAuth2 and IAM.
• Strong communication skills in English and Polish, with readiness to work in a hybrid model in Katowice.