Regular Kotlin Developer (f/m/x)

Sii Poland

Piła

On-site

PLN 140,000 - 210,000

Full time

9 days ago

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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 seeking a skilled backend software engineer to join our fintech platform team in Poland. You will design, build, and maintain Kotlin-based microservices, collaborating with Platform, Services, SMB, and other domains to deliver robust financial solutions.

The role focuses on scalable backend systems, cloud exposure (AWS, Kubernetes), PostgreSQL, testing with JUnit, and observability with Grafana. Fluent English required; Polish residence is expected.

Qualifications

3+ years of professional software development experience.
Hands-on Kotlin in commercial projects.
Experience building backend systems and working with microservices architecture.
Basic experience with cloud environments (AWS, Kubernetes).
Experience with relational databases (PostgreSQL) and testing/observability tools (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

Backend development

Microservices

AWS

Kubernetes

PostgreSQL

JUnit

Grafana

English

Tools

PostgreSQL

JUnit

Grafana

Job description

Join a team working on a modern fintech platform that supports company expense management. The project focuses on developing a finance solution that enables seamless integration of financial tools (including payment cards, expense management, and invoice handling) directly into partner systems such as banks, accounting platforms, and HR solutions. The product allows companies to simplify financial processes, automate settlements, and gain full real-time control over their spending.

Your tasks

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

Requirements

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

Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws.

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