Project FuSSE: Exploring flexible, scalable and secure settlement engines

Financial market infrastructures (FMIs) must remain secure, resilient and adaptable over long horizons, even as payment volumes grow and technologies, standards and threat environments evolve. The continued expansion of digital payments, alongside emerging models such as Internet of Things (IoT)-based payments, AI-driven commerce and broader fintech participation, raises new demands for scalability, flexibility and cyber resilience.

This report details the findings from Project FuSSE (Fully Scalable Settlement Engine), a proof-of-concept exploring how a modular, microservices-based architecture could support the design of settlement systems that could scale under sustained growth and stress conditions, adapt to change, and strengthen security through quantum readiness and cryptographic agility. The project demonstrated technical feasibility while highlighting significant operational trade-offs that must be carefully managed.

Key findings

Under controlled test conditions, the proof-of-concept demonstrated the feasibility of processing high transaction volumes, achieving 10,000 transactions per second (TPS), while scaling computing resources less than proportionally as throughput increased. By enabling independent scaling of services, including cryptographic services, the architecture illustrates one way to manage performance bottlenecks and support the integration of post-quantum cryptography (PQC) as standards mature. Clear service boundaries also facilitate future adaptation to evolving security, message and regulatory requirements.

Trade-offs and operational considerations

The report highlights key trade-offs: microservices increase operational complexity and attack surface, while PQC can add computational and bandwidth overhead, requiring careful orchestration. It also underscores the need for operational agility, including adaptable governance, certification and incident-response frameworks.

About this report

• Project FuSSE is an experimental proof-of-concept exploring architectural feasibility.
• It does not provide production-ready components, assert PFMI compliance, or define payment, governance or cost models.
• The findings are not a performance benchmark or implementation reference.