Kotlin Backend Engineer — Fintech Microservices

Sii Poland; Toruń; On-site; PLN 150,000 - 220,000; Full time

Benefits offered by this job

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 trips

Comfortable and well-equipped offices

MySii app

Medical care

Job summary

Sii Poland is hiring for a backend software engineer to design, build, and maintain microservices using Kotlin in a fintech-focused platform. You will work with cross-functional teams across Platform, Services, SMB, and other domains to deliver scalable solutions.

The role includes monitoring system performance, participating in code reviews, and continuously improving code quality and system architecture. Fluent English and Poland residence are required.

Qualifications

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

Responsibilities

• Design, build, and maintain microservices using Kotlin.
• Collaborate with cross-functional teams to deliver solutions across Platform, Services, SMB, and other domains.
• Support system performance monitoring and contribute to reliability and scalability improvements.
• Participate in code reviews and maintain high code quality standards.
• Contribute to continuous improvement of code quality and system architecture.
• Troubleshoot and resolve technical issues.

Skills

Cross-functional collaboration

Code reviews

Troubleshooting

Tools

Kotlin

AWS

Kubernetes

PostgreSQL

JUnit

Grafana

Job description

Sii Poland is hiring for a backend software engineer to design, build, and maintain microservices using Kotlin in a fintech-focused platform. You will work with cross-functional teams across Platform, Services, SMB, and other domains to deliver scalable solutions.

The role includes monitoring system performance, participating in code reviews, and continuously improving code quality and system architecture. Fluent English and Poland residence are required.