Principal Software Engineer, EU Engineering - Departments · Paris · Full-time · - [...]

Join a team of engineers and cryptographers building the infrastructure behind the next generation of financial systems. We’re hiring a Principal Software Engineer to lead the design and evolution of our core backend systems. You’ll drive the architecture of the services that power wallet operations, transaction processing, and integrations across multiple blockchains. You’ll set technical direction across critical parts of the platform, ensuring our systems remain fast, reliable, and secure as they scale. This role goes beyond implementation. You’ll guide architectural decisions, raise engineering standards, and mentor senior engineers. You’ll work closely with product, security, and leadership to align technical execution with company priorities and ensure our infrastructure performs under real-world financial workloads. Responsibilities Lead the design and development of scalable, secure backend services and APIs. Define and evolve architecture for databases, microservices, and integrations. Own mission‑critical projects end to end, from requirements to production and iteration. Troubleshoot and resolve complex performance and reliability challenges at scale. Collaborate with leadership to shape roadmap priorities and long‑term technical vision. Mentor engineers, promote best practices, and represent Dfns in client discussions. Requirements 10+ years of backend software engineering, with leadership in fintech or blockchain. Mastery of Type

Script, proven track record building scalable APIs and dev tools. Deep expertise with databases (Postgre

SQL, Dynamo

DB, No

SQL) and cloud (AWS). Strong knowledge of microservices, CI/CD pipelines, observability, and SSDLC. Familiar with public key infrastructure and secure backend architectures. Exceptional problem‑solving, communication, and ability to influence technical direction. Terms Title: Principal Software Engineer Salary: €120,000–200,000 per year (full‑time) Equity: 150–300 stock options vest