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 o f f inanc ial t echnology . 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