Synced from Greenhouse · Oct 28

Java Software Engineer - FinTech

FlixTrainWarsaw, PolandPosted Oct 28, 2026
Backend EngineerMid
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Oct 28
Posted
Greenhouse
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Job descriptionReq 8921675002

Rate: 89 – 119 / hour (B2B)

We are looking for a skilled Java Engineer to join Flix on a freelance/service agreement basis (B2B contract). This is a contractor engagement to work on impactful, hands-on challenges in the domain of financial technology. 

Scope of Services

Bring expertise in Java-based backend development. Work across Flix's finance technology environment to build and maintain critical internal applications — from revenue accounting, invoices processing to bus partner settlements and payment reconciliation.

About the Engagement

  • Design, build, and maintain features for the internal data-heavy applications, supporting automated bus partner settlement generation across all FlixBus entities around the globe.  
  • Develop and enhance the internal services that allow finance and billing teams to manage bus partners' settlement-relevant data and track changes via event history.  
  • Communicate directly with business counterparts (finance, billing, and partner teams) to understand needs and shape solutions. 
  • Actively participate in product development, from refinement and technical design through delivery and operations. 
  • Implement and maintain event-driven data processing workflows using Kafka to support settlement operations. 
  • Contribute to infrastructure-as-code practices and CI/CD pipelines on AWS, and run services on Docker/Kubernetes, with monitoring and observability (e.g. Datadog).  

About You

  • At least 3 years of experience as a Software Engineer, with exposure to data processing systems  
  • Proven experience working with Java in a commercial environment  
  • Experience with event-driven architectures, ideally Kafka 
  • Experience working with cloud-based infrastructure providers, ideally AWS  
  • Solid SQL knowledge 
  • Hands-on experience with Docker and Kubernetes (or similar container orchestration tools) and CI/CD 
  • Familiarity with Snowflake or similar data warehousing solutions is a plus 
  • Experience in front-end technologies (e.g., JavaScript, HTML5, React.js, or Angular) is a plus  
  • Fluent in English

Cooperation model

  • Cooperation based on a service agreement (B2B/freelance contract), not an employment contract.
  • You will operate as an independent contractor, responsible for delivering agreed services and submitting invoices 
  • Location: open for contractors based in Poland

 

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Java Software Engineer - FinTech
FlixTrain · Warsaw, Poland
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