Backend Engineer (Java, Kotlin)

Reply; Katowice; Hybrid; PLN 100,000 - 145,000; Full time

Benefits offered by this job

Salary 9000-13000 PLN gross/month

Motivizer Benefits Platform with 550PL

Language Courses

Regular training opportunities

Networking events & company parties

Job summary

OBI Smart Technologies, a joint venture between OBI and Reply Group, seeks a backend engineer to develop scalable Kotlin/Java backend services powering product and assortment management in a large retail ecosystem.

You will work in a hybrid model in Katowice, collaborating with product owners and engineers to build reliable systems, design data models, and implement event-driven architectures using Kafka.

Qualifications

• University degree in Computer Science or equivalent.
• 3–5 years of backend experience with Kotlin/Java and Spring Boot.
• Strong knowledge of REST APIs, microservices, and distributed systems.
• Hands-on experience with Kafka or similar messaging systems.
• Experience with PostgreSQL and data modeling.
• Familiar with CI/CD, containerization, and basic security concepts (OAuth 2.0, IAM).
• Excellent English and Polish, with willingness to work in a hybrid model in Katowice.

Responsibilities

• Develop and maintain backend services, APIs, and integrations using Kotlin and Spring Boot.
• Translate business and product data requirements into scalable backend solutions.
• Contribute to event-driven architectures and Kafka-based processing.
• Support cloud-native and containerized deployments.
• Design and maintain data models and persistence with PostgreSQL.
• Collaborate with product, business, and engineering teams to refine requirements and deliver features.
• Contribute to code quality, testing, observability, and reliability.

Skills

Backend development

REST APIs

Microservices

Distributed systems

English & Polish

Education

Bachelor in CS

Tools

Kafka

PostgreSQL

OAuth 2.0

IAM

Kubernetes

Job description

We are looking for a backend engineer who wants to develop and evolve systems powering product and assortment management within a large retail ecosystem.

You will contribute to building scalable backend services and integrations within the assortment management domain, 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 and Spring Boot.
• Translate business and product data 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.

Benefits

• Salary range for Employment Contract: 9 000 - 13 000 PLN gross/month.
• 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.
• 3–5 years of professional experience in backend development using Kotlin or Java with Spring Boot.
• Good understanding of REST APIs, microservices, and distributed systems.
• Hands‑on experience or exposure to Kafka or similar messaging systems.
• Experience working with PostgreSQL and designing reliable data models.
• Familiarity with CI/CD, containerization, and basic security concepts (OAuth 2.0, IAM).
• Strong communication skills in English and Polish, with readiness to work in a hybrid model in Katowice.

Nice to have:

• Experience with AWS and Kubernetes (e.g., Amazon EKS).
• Experience with event-driven architectures in production environments.
• Familiarity with observability tools and monitoring practices.

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.