Java Software Engineer

Software Engineer (Java / Treasury Platform) Location: Hong Kong (Looking for candidates available to start immediately) About Lightnet Lightnet Group is a leading Fintech enterprise headquartered in Singapore with a global footprint across APAC and Europe. We build next-generation financial infrastructure to bridge legacy banking rails with digital-asset liquidity, delivering real-time cross-border payments, settlement platforms, and financial services for institutional clients, SMEs, and digital-native businesses. We are expanding our core engineering team in Hong Kong to build Project Helios—Lightnet’s next-generation, real-time Treasury and On/Off-Ramp Platform. Helios serves as the high-throughput engine managing multi-currency liquidity, automated double-entry ledger systems, inventory-book netting, and smart order routing across international banking partners and institutional digital-asset venues. The Role We are seeking a Java Developer to drive the technical design and backend delivery of Project Helios. In this role, you will architect and build low-latency, resilient distributed treasury services using cutting-edge Java technologies. You will work on various micro-services or components, including pricing engine, order execution engine, risk & hedging engine, settlement, custody and accounting services. Key Responsibilities ● Core Platform Development: Architect, build, and maintain high-performance, real-time backend microservices for Project Helios using Java 25 (Virtual Threads), Reactive Java, and Spring Boot. ● System Design & Event-Driven Architecture: Design event-driven workflows utilizing asynchronous message queues and distributed caching for order lifecycle state machines, real-time price stream ingestion, and inventory-book hedge triggers. ● Financial Ledger & Transaction Integrity: Design and maintain immutable, secure double-entry ledger systems and automated EOD reconciliation engines backed