Java Software Engineer - FinTech

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