Senior Software Engineer, Java
FDJ UNITED is seeking a Senior Software Engineer to focus on their Sportsbook product. The role involves building and evolving a next-generation trading risk platform that powers real-time liability and exposure management across multiple brands and markets.
The successful candidate will primarily work on the Core Liability engine, which is a modular, event-driven system. This platform is designed to deliver fast, accurate, and real-time insight into live positions and risk, representing a significant advancement in scalability, resilience, and streaming architecture for the organisation.
- Design and build distributed, real-time streaming components within a Flink-based architecture.
- Develop and maintain services that process the full bet lifecycle, from acceptance through settlement, cancellation, and cashout.
- Implement complex financial calculations, including multi-bet and bet-builder logic, ensuring accuracy and consistency at scale.
- Build systems that aggregate exposure and generate real-time risk insights across outcomes, markets, and customers.
- Contribute to a granular alerting framework that detects and publishes meaningful changes in liability.
- Ensure correctness in a high-throughput environment through robust handling of ordering, duplication, and idempotency.
- Optimise streaming jobs for latency, throughput, and resource efficiency.
- Collaborate closely with trading and product teams to translate domain requirements into scalable, reliable systems.
- Contribute to a modular architecture where components evolve independently and scale with increasing demand.
- 5+ years software engineering experience in building distributed systems. (required)
- Excellent Java skills. (required)
- Experience with streaming technologies (Apache Flink preferred; Kafka Streams, Spark Streaming, etc.). (preferred)
- Solid understanding of event-driven architecture and asynchronous processing patterns. (required)
- Experience handling data consistency challenges such as at-least-once processing, idempotency, and event ordering. (required)
- Experience building high-throughput, low-latency systems in production environments. (required)
- Ability to model complex domain logic and translate business requirements into robust technical solutions. (required)
- Experience in cloud computing, ideally AWS. (required)
- Proactive and ability to deal with and account for uncertainty, with the flexibility to learn by iteration. (required)
- Experience in sports betting, trading platforms, or financial systems. (nice-to-have)
- Experience building real-time alerting or monitoring systems. (nice-to-have)
- Exposure to modern data platforms or lakehouse architectures. (nice-to-have)
FDJ United is one of Europe's largest gaming and betting groups, formed after French lottery operator La Française des Jeux (FDJ) acquired Kindred Group - the company behind Unibet - in 2024 and rebranded the enlarged group in 2025. Headquartered in Boulogne-Billancourt, France, it operates lottery, online sports betting, casino and poker across multiple European markets and Australia. Its portfolio includes well-known online brands such as Unibet, 32Red and Maria Casino, alongside FDJ's French lottery and retail network. The group is listed on the Euronext Paris exchange.