Senior Kotlin Engineer - Microservices & Cloud (AWS/K8s)

Sii Sp. z o.o.

Lublin

On-site

PLN 180,000 - 240,000

Full time

14 days+

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Benefits offered by this job

Great Place to Work

Profit sharing

Private healthcare

Remote-friendly options

Professional growth

Global projects

Ideas incentive program

Tech talks & trainings

Dynamic team culture

Job summary

Sii Sp. z o.o. is seeking a Kotlin Developer to join a fintech-focused team in Lublin, Poland. You will design, build, and maintain scalable microservices primarily in Kotlin, collaborating with cross-functional teams to deliver reliable solutions.

The role requires 5+ years of software development experience, strong Kotlin and cloud skills, PostgreSQL, and English proficiency. On-site work in Lublin is expected with a comprehensive benefits package.

Qualifications

Minimum 5 years of professional software development experience.
Expertise in Kotlin and distributed systems, microservices, and cloud environments (AWS, Kubernetes).
Proficiency with PostgreSQL, testing tools (JUnit, Testcontainers), and Grafana for observability.
Strong problem-solving skills and collaborative mindset to mentor teammates.
Excellent English skills (min. B2).
Residence in Poland is required.

Responsibilities

Lead design, build, and maintenance of scalable microservices using Kotlin.
Collaborate with cross-functional teams across Platform, Services, SMB, and more.
Analyze performance and implement optimizations for reliability and scalability.
Participate in code reviews, post-mortems, and mentor engineers.
Improve architecture and guide the team through technical challenges and migrations.