Kotlin Backend Engineer for Fintech Microservices

Sii Poland; Rzeszów; On-site; PLN 220,000 - 320,000; 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 in Rzeszów is seeking a backend software engineer to join a modern fintech platform for expense management. You will design, build, and maintain Kotlin-based microservices that integrate with partner systems such as banks, accounting platforms, and HR solutions.

You will collaborate with cross-functional teams across Platform, Services, SMB and other domains, support performance monitoring, and contribute to reliability, scalability and code quality.

Qualifications

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

Responsibilities

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

Skills

Kotlin

Backend development

Microservices

AWS

Kubernetes

PostgreSQL

JUnit

Grafana

English

Poland resident

Tools

JUnit

Grafana

AWS

Kubernetes

Job description

Sii Poland in Rzeszów is seeking a backend software engineer to join a modern fintech platform for expense management. You will design, build, and maintain Kotlin-based microservices that integrate with partner systems such as banks, accounting platforms, and HR solutions.

You will collaborate with cross-functional teams across Platform, Services, SMB and other domains, support performance monitoring, and contribute to reliability, scalability and code quality.