Kotlin Backend Engineer — Fintech Microservices

Sii Poland; Łódź; 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

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 backend developer to design, build, and maintain microservices in Kotlin for a fintech platform. You will work with cross-functional teams to deliver scalable solutions and help ensure performance and reliability across the system architecture.

The role requires 3+ years of experience in software development, strong Kotlin skills, and hands-on knowledge of cloud environments and database/observability tools.

Qualifications

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

Responsibilities

• Designing, building, and maintaining microservices using Kotlin.
• Collaborating with cross-functional teams across Platform, Services, SMB, and other domains.
• Supporting performance monitoring and improvements in reliability and scalability.
• Participating in code reviews and maintaining high code quality standards.
• Contributing to continuous improvement of code quality and system architecture.
• Troubleshooting and resolving technical issues.

Skills

Kotlin

Backend development

Microservices

Cloud environments

PostgreSQL

Observability tools

English

Tools

AWS

Kubernetes

PostgreSQL

JUnit

Grafana

Job description

Sii Poland is seeking a backend developer to design, build, and maintain microservices in Kotlin for a fintech platform. You will work with cross-functional teams to deliver scalable solutions and help ensure performance and reliability across the system architecture.

The role requires 3+ years of experience in software development, strong Kotlin skills, and hands-on knowledge of cloud environments and database/observability tools.