Kotlin Backend Engineer - Fintech Microservices

Sii Poland; Poznań; On-site; PLN 120,000 - 190,000; 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

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 an experienced backend developer to join a fintech platform focused on expense management and integration with banks, accounting, and HR systems. The role emphasizes building scalable microservices in Kotlin and collaborating with cross-functional teams.

You will help ensure performance, reliability, and real-time control over spending, participate in code reviews, and contribute to architecture improvements.

Qualifications

• Minimum 3 years of professional software development experience.
• Hands-on experience with Kotlin in commercial projects.
• Experience building backend systems with microservices architecture.
• Basic experience with cloud environments (e.g., AWS, Kubernetes).
• Experience with PostgreSQL and testing/observability tools (JUnit, Grafana).
• Strong English communication skills.
• Residence in Poland is 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

Cloud environments

PostgreSQL

Tests & observability

English

Tools

JUnit

Grafana

AWS

Kubernetes

Job description

Sii Poland is seeking an experienced backend developer to join a fintech platform focused on expense management and integration with banks, accounting, and HR systems. The role emphasizes building scalable microservices in Kotlin and collaborating with cross-functional teams.

You will help ensure performance, reliability, and real-time control over spending, participate in code reviews, and contribute to architecture improvements.