Lead Kotlin Microservices Engineer (Fintech)

Sii Poland; Kraków; On-site; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Centre of internal trainings

Profit sharing

Medical care

Great Place to Work

Contract with major brands

Job summary

Sii Poland is seeking a senior backend engineer to design, build, and maintain scalable microservices in Kotlin as part of a modern fintech platform. You will collaborate with cross-functional teams across Platform, Services, SMB, and more to deliver reliable, scalable solutions.

Join a team that values architecture, code quality, and mentorship, with opportunities for growth in aFintech-focused environment and a strong emphasis on cloud-native technologies in Poland.

Qualifications

• 5+ years of professional software development experience.
• Kotlin expert with server-side and distributed systems/microservices experience.
• Experience with AWS or Kubernetes and cloud environments.
• Relational databases like PostgreSQL and observability tools (Grafana).
• Strong problem-solving and mentoring mindset.
• English at least B2 level.
• Residing in Poland.

Responsibilities

• Design, build, and maintain scalable microservices mainly using Kotlin.
• Collaborate with cross-functional teams across Platform, Services, SMB, and other domains.
• Analyze system performance and implement optimizations for reliability and scalability.
• Participate in code reviews, post-mortems, and mentor engineers.
• Improve architecture and quality, leading migrations and technical challenges.

Skills

Kotlin

Distributed systems

Microservices

Cloud environments

English (B2)

Tools

AWS

Kubernetes

PostgreSQL

JUnit

Testcontainers

Grafana

Job description

Sii Poland is seeking a senior backend engineer to design, build, and maintain scalable microservices in Kotlin as part of a modern fintech platform. You will collaborate with cross-functional teams across Platform, Services, SMB, and more to deliver reliable, scalable solutions.

Join a team that values architecture, code quality, and mentorship, with opportunities for growth in aFintech-focused environment and a strong emphasis on cloud-native technologies in Poland.