Kotlin Full-Stack Engineer (Freelance/Service Agreement)

Warsaw Until 9/26/2026 5+ years exp H-1B sponsor history First posted July 28, 2026 Last posted July 28, 2026
Job description

We are looking for a skilled Senior (Full-Stack) Kotlin Engineer as service agreement collaborator. Flix customers worldwide expect a comfortable and seamless experience at our stations as part of their travel experience. Our self-organized, cross-functional and distributed team builds products to enable Flix station managers to scale management of the station inventory, which a wide range of internal tech teams across Flix depend on, and overall serves to improve the experience at our stations for millions of passengers.

Scope of services

  • Independent management of roadmap epics as topic driver, aligning technical requirements and solutions across the Flix teams together with the product owner
  • Close interaction with business stakeholders on continuously developing and improving the product vision with business driven mindset
  • Supporting the development process using an agile environment
  • Pair and ensemble programming, code reviews, testing, and operations
  • Delivery of new versions of the product, using continuous integration and delivery

Relevant experience

  • 5+ years of software engineering experience, primarily backend development with a JVM language, including some commercial experience with Kotlin
  • Solid front-end skills with modern front-end stack
  • Experience with event-driven architectures; exposure to event sourcing, CQRS, and domain-driven design (DDD) is a plus
  • Hands-on experience with automation and deployment of applications into cloud infrastructure (e.g., AWS, Azure) using CI/CD pipelines and DevOps best practices
  • Proficiency in system design and architecture
  • Solid written and spoken English communication skills

 

 

About this role

Summary

Developing and maintaining Kotlin-based backend and front-end systems in an agile environment.

Job title

Kotlin Full-Stack Engineer

Experience level

5+ years

Minimum experience

5+ years exp

Industry

software

Location requirements

based in Warsaw, remote work allowed

Salary

Not specified

Visa sponsorship

H-1B sponsor history

Management role

No

Skills & keywords

Required skills

Kotlinbackendfront-endcloudci/cd

Preferred skills

event sourcingcqrsdddawsazure

Specializations

backendfrontendcloudarchitecture
Locations

Structured locations inferred from the posting.

Warsaw, Poland

Remote City