Kotlin Backend Engineer – Fintech Microservices

Sii Poland; Szczecin; On-site; PLN 150,000 - 210,000; Full time

Benefits offered by this job

Great Place to Work

Profit sharing

Medical care

Centre of internal trainings

Learning from experts

Job summary

Sii Poland is seeking a backend engineer to contribute to a modern fintech platform focused on expense management and seamless integration with partner systems.

You will design, build, and maintain Kotlin-based microservices, collaborate with cross-functional teams, and help improve reliability, performance, and architecture. The role requires strong English skills and residence in Poland.

Qualifications

• Minimum 3 years of professional experience in software development.
• Hands-on experience with Kotlin in commercial projects.
• Experience building backend systems and working with microservices architecture.
• Basic experience with cloud environments (e.g., AWS, Kubernetes).
• Experience with relational databases (e.g., PostgreSQL) as well as testing and observability tools (e.g., JUnit, Grafana).
• Good command of English.
• Residing in Poland required.

Responsibilities

• Designing, building, and maintaining microservices using Kotlin.
• Collaborating with cross-functional teams to deliver solutions across Platform, Services, SMB, and other domains.
• Supporting system performance monitoring and contributing to improvements in reliability and scalability.
• Participating in code reviews and maintaining high code quality standards.
• Contributing to the continuous improvement of code quality and system architecture.
• Troubleshooting and resolving technical issues.

Skills

Kotlin

Microservices

Cloud environments (AWS, Kubernetes)

Relational databases (PostgreSQL)

Testing & observability (JUnit, Grafia

Tools

Kotlin

PostgreSQL

AWS

Kubernetes

JUnit

Grafana

Job description

Sii Poland is seeking a backend engineer to contribute to a modern fintech platform focused on expense management and seamless integration with partner systems.

You will design, build, and maintain Kotlin-based microservices, collaborate with cross-functional teams, and help improve reliability, performance, and architecture. The role requires strong English skills and residence in Poland.