Lead Kotlin Engineer – Fintech Microservices

Sii Poland; Szczecin; On-site; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Great Place to Work

Centre of internal trainings

Profit sharing

Medical care

Job summary

Sii Poland in Szczecin is seeking a senior software engineer to lead design, build and maintain scalable Kotlin-based microservices for a modern fintech platform integrating financial tools into partner systems.

You will collaborate with cross-functional teams across Platform, Services, SMB and more, optimize performance, participate in code reviews, and mentor teammates through technical challenges and migrations.

Qualifications

• 5+ years of professional software development experience.
• Expertise in Kotlin, distributed systems, microservices, and cloud environments (AWS, Kubernetes).
• Proficiency with PostgreSQL, testing (JUnit, Testcontainers), and observability (Grafana).
• Strong problem-solving and mentoring mindset.
• Very good English (B2).
• Residing in Poland required.

Responsibilities

• Leading design, build, and maintenance of scalable Kotlin-based microservices.
• Collaborating with cross-functional teams across Platform, Services, SMB, and other domains.
• Analyzing performance and implementing optimizations for reliability and scalability.
• Participating in code reviews, post-mortems, and mentoring engineers.
• Driving architecture improvements and leading migrations through technical challenges.

Job description

Sii Poland in Szczecin is seeking a senior software engineer to lead design, build and maintain scalable Kotlin-based microservices for a modern fintech platform integrating financial tools into partner systems.

You will collaborate with cross-functional teams across Platform, Services, SMB and more, optimize performance, participate in code reviews, and mentor teammates through technical challenges and migrations.