Senior Java Developer with Apache Kafka (f/m/x)

Sii Poland; Bydgoszcz; On-site; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Great Place to Work

Profit sharing

Centre of internal trainings

Many experts you can learn from

Open and accessible management team

Regular integration events and trips

MySii app

Medical care

Job summary

Sii Poland in Poland seeks an experienced Senior Java Developer to join a team building a modern enterprise data integration and processing platform. You will develop scalable backend services, microservices, and event-driven integrations, modernizing legacy applications in line with Domain-Driven Design and cloud-ready solutions.

You will actively participate in architecture discussions, contribute to technical decisions, and use Apache Kafka to enable efficient data processing across

Qualifications

• At least 10 years of commercial software development with Java backend focus.
• Strong production experience with Apache Kafka.
• Experience designing and building microservices and event-driven architectures.
• Experience with distributed systems and enterprise integrations.
• Ability to contribute independently to technical design discussions.
• Excellent English communication in an international environment; residence in Poland.
• CCDAK certification is required or in hand.

Responsibilities

• Design, develop, and maintain scalable backend services and microservices using Java and Spring Boot.
• Implement event-driven data-processing solutions based on Apache Kafka.
• Build enterprise integrations between internal and external systems via APIs, messaging, and asynchronous communication.
• Participate in technical design and solution architecture discussions.
• Support modernization of legacy applications into scalable, cloud-ready solutions.
• Monitor, troubleshoot, and optimize performance across distributed environments.
• Collaborate with developers, architects, and stakeholders on data integration initiatives.

Skills

Java backend

Apache Kafka

Microservices

Distributed systems

Technical design

English communication

Education

CCDAK certification

Job description

We are looking for an experienced Senior Java Developer to join a team building a modern enterprise data integration and processing platform that supports key logistics and transportation processes on a global scale. This role focuses on developing scalable backend services, microservices, and event-driven integrations within a complex enterprise environment.

You will contribute to the design and implementation of solutions that enable efficient data processing and communication across business systems. An important part of the role involves modernizing legacy applications and delivering solutions aligned with Domain-Driven Design principles.

We are looking for a self-driven professional who can actively participate in architecture discussions and make sound technical decisions. Strong hands-on production experience with Apache Kafka is essential for success in this role.

Your tasks

• Designing, developing, and maintaining scalable backend services and microservices using Java and Spring Boot
• Implementing event-driven architectures and data-processing solutions based on Apache Kafka
• Building enterprise integrations between internal and external systems using APIs, messaging platforms, and asynchronous communication mechanisms
• Participating in technical design and solution architecture discussions, providing expertise in distributed systems and integration patterns
• Supporting the modernization and transformation of legacy applications into scalable, maintainable, and cloud-ready solutions
• Monitoring, troubleshooting, and optimizing application performance, reliability, and scalability across distributed environments
• Collaborating closely with developers, architects, and business stakeholders to deliver strategic data integration and digital transformation initiatives

Requirements

• Minimum 10 years of commercial software development experience, including strong senior-level expertise in Java backend development
• Strong hands-on production experience with Apache Kafka
• Proven experience designing and building microservices, scalable backend services, and event-driven architectures
• Practical experience working with distributed systems, enterprise integrations, and data processing solutions
• Ability to contribute independently to technical design and solution architecture discussions
• Very good English communication skills, enabling effective collaboration in an international environment
• Residence in Poland
• Valid Confluent Certified Developer for Apache Kafka (CCDAK) certification

Nice to have

• Production experience with Kafka Streams and Kafka Connect
• Experience with cloud-native and containerized environments, including Azure, Kubernetes, OpenShift, Docker, or Podman

Job no. JOB-DGAMP

Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws.

Benefits For You

• Great Place to Work
• Solid financial situation
• Contracts with the biggest brands
• Centre of internal trainings
• Many experts you can learn from
• Open and accessible management team
• Profit sharing
• Passion Sponsorship program
• Regular integration events and tripsComfortable and well-equipped offices
• MySii app
• Medical care