Regular Kotlin Developer (f/m/x)

Sii Poland

Białystok

On-site

PLN 150,000 - 210,000

Full time

14 days+

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Benefits offered by this job

Great Place to Work

Centre of internal trainings

Profit sharing

Medical care

Open and accessible management team

Job summary

Sii Poland is seeking a skilled Backend Kotlin Developer to join a fintech platform enhancing company expense management. You will design and maintain microservices, collaborate with Platform, Services, and SMB teams, and contribute to performance monitoring and reliability improvements.

The role requires 3+ years in software development, Kotlin in commercial projects, backend and microservices experience, and familiarity with AWS/Kubernetes, PostgreSQL, JUnit, and Grafana.

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

Backend development

Microservices architecture

Cloud environments

Relational databases

Testing & observability

English

Tools

PostgreSQL

JUnit

Grafana

AWS

Kubernetes

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

Job no. JOB-R7LMQ

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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