Senior Kotlin Backend Engineer for Scalable Microservices

Sii; Poznań, Szczecin; On-site; PLN 180,000 - 240,000; Full time

Job summary

Sii in Poznań, Poland, is seeking an experienced Senior Kotlin Developer to join a modern backend platform. You will design, implement, and optimize scalable microservices, work with external systems, and influence technical decisions to boost performance and reliability.

You will collaborate with cross-functional teams to deliver high-quality software, participate in code reviews, and mentor colleagues while adopting best practices and modern development tools.

Qualifications

• Minimum 3 years of professional software development experience with Java and Kotlin.
• Solid experience designing and developing microservice-based applications.
• Advanced English skills.

Responsibilities

• Design, develop, and enhance scalable backend services using Kotlin.
• Collaborate with product, engineering and other teams to deliver technical solutions.
• Monitor performance and identify opportunities to improve scalability, stability, and efficiency.
• Contribute to code reviews and technical discussions to maintain high standards.
• Support continuous improvements in development practices and code quality.
• Share knowledge and mentor team members.

Skills

Kotlin

Java

Microservices

English

Tools

Kubernetes

AWS

Apache Kafka

React.js

TypeScript

Job description

Sii in Poznań, Poland, is seeking an experienced Senior Kotlin Developer to join a modern backend platform. You will design, implement, and optimize scalable microservices, work with external systems, and influence technical decisions to boost performance and reliability.

You will collaborate with cross-functional teams to deliver high-quality software, participate in code reviews, and mentor colleagues while adopting best practices and modern development tools.