Lead Kotlin Microservices Engineer – Fintech Platform

Sii Poland; Białystok; On-site; PLN 170,000 - 230,000; 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 in Białystok is seeking an experienced software engineer to join a modern fintech platform focusing on expense management, payments, and integration with partner systems. You will design, build, and maintain Kotlin-based microservices and collaborate across Platform, Services, SMB.

The role demands 5+ years in software development, expertise in Kotlin, distributed systems, cloud environments (AWS, Kubernetes), PostgreSQL, and observability tools.

Qualifications

• Minimum 5 years of professional experience in software development.
• Expertise in Kotlin and server-side languages; distributed systems, microservices, and cloud environments (AWS, Kubernetes).
• Proficiency with PostgreSQL, testing frameworks (JUnit, Testcontainers), and observability tools like Grafana.
• Strong problem-solving and mentoring mindset.
• Proficiency in English (B2).
• Residing in Poland required.

Responsibilities

• Leading initiatives to design, build, and maintain scalable microservices primarily using Kotlin
• Collaborating with cross-functional teams to develop innovative solutions across Platform, Services, SMB, and other domains
• Analyzing system performance and implementing optimizations to ensure high reliability and scalability
• Participating in code reviews, post-mortems, and providing mentorship to other engineers
• Proactively improving the architecture and quality of solutions, and leading the team through technical challenges and migrations

Skills

Kotlin

Distributed systems

Microservices

Cloud (AWS, Kubernetes)

PostgreSQL

JUnit/Testcontainers

Grafana observability

English (B2)

Tools

JUnit

Testcontainers

Grafana

Job description

Sii Poland in Białystok is seeking an experienced software engineer to join a modern fintech platform focusing on expense management, payments, and integration with partner systems. You will design, build, and maintain Kotlin-based microservices and collaborate across Platform, Services, SMB.

The role demands 5+ years in software development, expertise in Kotlin, distributed systems, cloud environments (AWS, Kubernetes), PostgreSQL, and observability tools.