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

Responsibilities

We are looking for a backend engineer who wants to develop and evolve digital products and services powering OBI PRO, our B2B business for professional customers, craftsman, and businesses within the OBI retail ecosystem.

You will contribute to building scalable backend services and integrations that support our B2B customer experience, sales processes, and digital services, working in an event-driven environment. You will collaborate closely with engineers, product owners, and architects to deliver reliable and maintainable solutions.

Your key responsibilities include

• Develop and maintain backend services, APIs, and integrations using Kotlin, Java and Spring Boot.
• Translate business and B2B customer requirements into scalable and maintainable backend solutions.
• Contribute to event-driven architectures and asynchronous processing using Kafka.
• Support the integration of backend systems within cloud-native and containerized environments.
• Design and maintain data models and persistence layers using PostgreSQL.
• Collaborate with product, business, and engineering teams to refine requirements and deliver features.
• Contribute to code quality, testing, observability, and system reliability.
• Actively use AI-powered development tools to improve productivity, code quality, and efficiency throughout the software development lifecycle.

Benefits

• Motivizer Benefits Platform to choose and manage all your benefits in one place. You receive a budget (550 PLN monthly). You can choose medical care package, meal tickets, sports cards (we have Multisport and on preferential terms, we have membership cards to one of the most popular Gyms), cinema tickets, shop vouchers, discounts and many more.
• Language Courses - you'll have access to a multi-language learning platform enabling you to practice your language skills and learn new ones!
• Regular and systematic further training opportunities - both internally and from external providers. We support your ongoing learning and development.
• Cooperation within an internal community is our everyday reality. We have networking events, coding challenges, and company parties for different occasions.

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 (OAuth2, IAM).
• Strong communication skills in English and Polish, with readiness to work in a hybrid model in Katowice.

About OBI Smart Technologies

Who are we

We are a joint venture between OBI and Reply Group, responsible for co-designing, building and operating mission-critical digital platforms for commerce, customer service, and omnichannel retail.

Our mission

"We unite technology leadership with deep retail vision to implement standardized processes and scalable digital products that drive efficient support for one of Europe’s largest DIY retailers. Leveraging proven best practices, we advance the internationalization of products and the digital mindset of our partners, delivering consistent and business-critical solutions to support the targets of our customer."