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

Quick Facts

• Role: Senior Backend Engineer (B2B)

• Focus: Backend services, APIs, integrations, event-driven architecture

Description

You will develop and evolve scalable backend services and integrations supporting OBI’s B2B digital customer experience, sales processes, and services. The work is done in an event-driven environment, collaborating with engineers, product owners, and architects to deliver reliable and maintainable solutions. Responsibilities include building Kotlin/Java Spring Boot services, Kafka-based asynchronous processing, and PostgreSQL persistence, along with cloud-native deployment support and strong engineering practices.

Responsibilities

• Develop and maintain backend services, APIs, and integrations using Kotlin, Java, and Spring Boot

• Translate business and B2B customer requirements into scalable backend solutions

• Implement event-driven architectures and asynchronous processing with Kafka

• Support integration of backend systems in cloud-native and containerized environments

• Design and maintain data models and persistence layers with PostgreSQL

• Collaborate across product, business, and engineering teams to refine requirements and deliver features

• Improve code quality, testing, observability, and system reliability

• Use AI-powered development tools to increase productivity, code quality, and efficiency

Requirements

• University degree in Computer Science or comparable technical field

• 6+ years backend development experience with Kotlin and Spring Boot in complex environments

• Strong expertise in REST APIs, microservices, distributed systems, and event-driven architectures

• Deep hands-on production experience with Kafka and asynchronous processing

• Strong AWS and Kubernetes experience, including Amazon EKS

• Solid PostgreSQL experience and ability to design performant, reliable data models

• Experience with CI/CD, containerization, observability tooling, and security concepts (OAuth2, IAM)

• Strong communication skills in English and Polish; readiness to work in a hybrid model in Katowice