Kotlin Backend Engineer for Fintech Microservices

Sii Poland; Warszawa; On-site; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Great Place to Work

Profit sharing

Centre of internal trainings

Many experts you can learn from

Open and accessible management team

Regular integration events and trips

Comfortable and well-equipped offices

MySii app

Medical care

Job summary

Sii Poland is seeking a Kotlin backend developer to design, build, and maintain microservices for a modern fintech platform in Warsaw. You will collaborate with cross-functional teams across Platform, Services, SMB, and other domains to deliver scalable backend solutions.

The role requires at least 3 years of professional software development experience, with hands-on Kotlin, cloud (AWS/Kubernetes), and PostgreSQL expertise. Excellent English is essential; Poland residency is required.

Qualifications

• 3+ years of professional software development experience.
• Proficient with Kotlin in commercial projects.
• Experience building backend systems with microservices.
• Knowledge of cloud environments (AWS, Kubernetes) preferred.
• Experience with relational DB (PostgreSQL) and testing/observability tools (JUnit, Grafana).
• Strong command of English and 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 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

Kotlin

Microservices

Backend development

AWS/Kubernetes

PostgreSQL

JUnit/Grafana

English

Tools

AWS

Kubernetes

PostgreSQL

JUnit

Grafana

Job description

Sii Poland is seeking a Kotlin backend developer to design, build, and maintain microservices for a modern fintech platform in Warsaw. You will collaborate with cross-functional teams across Platform, Services, SMB, and other domains to deliver scalable backend solutions.

The role requires at least 3 years of professional software development experience, with hands-on Kotlin, cloud (AWS/Kubernetes), and PostgreSQL expertise. Excellent English is essential; Poland residency is required.