Senior Java Backend Engineer | Kafka & Microservices

Sii Poland; Warszawa; On-site; PLN 200,000 - 320,000; Full time

Benefits offered by this job

Great Place to Work

Centre of internal trainings

Profit sharing

Regular integration events and trips

Medical care

Job summary

Sii Poland in Warsaw is seeking an experienced Senior Java Developer to join a team building a modern data integration and processing platform supporting logistics on a global scale. You will design scalable backend services and microservices using Java and Spring Boot, with a focus on event-driven integrations via Apache Kafka.

The role requires hands-on production Kafka experience, architecture input, and collaboration with cross-functional teams to modernize legacy apps into cloud-ready

Qualifications

• Minimum 10 years of commercial software development experience.
• Strong senior-level Java backend expertise.
• Production experience with Apache Kafka.
• Experience designing microservices and event-driven architectures.
• Experience with distributed systems and enterprise integrations.
• Fluent English communication in international environments.
• Residence in Poland.
• CCDAK certification (Confluent Certified Developer for Apache Kafka).

Responsibilities

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

Skills

Java backend development

Event-driven architectures

Microservices design

Distributed systems

Kafka expertise

English communication

Architectural discussions

Tools

Apache Kafka

Kafka Streams

Kafka Connect

Kubernetes

OpenShift

Docker/Podman

Job description

Sii Poland in Warsaw is seeking an experienced Senior Java Developer to join a team building a modern data integration and processing platform supporting logistics on a global scale. You will design scalable backend services and microservices using Java and Spring Boot, with a focus on event-driven integrations via Apache Kafka.

The role requires hands-on production Kafka experience, architecture input, and collaboration with cross-functional teams to modernize legacy apps into cloud-ready