Senior Kotlin Backend Developer

Qulix Systems; Wrocław; Hybrid; PLN 327,000 - 479,000; Full time

Job summary

Qulix Systems is hiring Senior Kotlin Backend Developers to join a nearshore team on a greenfield accounting engine project. You will build a central platform handling invoices, receipts, and transactions for new markets.

The role requires strong Kotlin, Spring Boot with WebFlux, AWS experience, and a solid grasp of DDD and TDD. Remote, full-time position with international collaboration to shape a scalable accounting solution.

Qualifications

• 5+ years of commercial Kotlin experience.
• Spring Boot & Spring Boot WebFlux proficiency.
• Experience with AWS.
• Experience with Event Sourcing.
• Strong understanding of DDD (Domain Driven Design).
• Experience with TDD (Test Driven Development).

Responsibilities

• Develop and maintain a greenfield accounting engine backend.
• Architect and implement scalable Kotlin microservices with Spring Boot WebFlux.
• Apply Event Sourcing and DDD best practices.
• Collaborate with nearshore team to deliver milestones and quality software.

Skills

Kotlin

Spring Boot

WebFlux

AWS

Event Sourcing

Domain Driven Design

Test Driven Development

Tools

jOOQ

Flyway

GitHub CI/CD

Hexagonal Architecture

Claude

Cursor

Job description

We're looking for Senior Kotlin Backend Developers to join a nearshore development team working on a greenfield project.

You'll be working on a new Accounting Engine that will become the central accounting platform for new markets, processing business events such as invoices, receipts, and transactions.

Location

Europe

Format

Full-time, remote

What we're looking for:

• At least 5 years of commercial experience with Kotlin
• Spring Boot & Spring Boot WebFlux
• AWS
• Experience with Event Sourcing
• Strong understanding of DDD (Domain Driven Design)
• Experience with TDD (Test Driven Development)

Additional skills:

• jOOQ / Flyway
• GitHub-based CI/CD
• Hexagonal Architecture
• Experience with AI-assisted development tools (Claude, Cursor)

We're looking for someone who enjoys solving complex technical challenges, takes ownership, and is excited to build a new platform from the ground up.