Senior Core Systems Engineer

Job Description This is a remote position. A Crypto wallet security infrastructure provider are looking for a Senior Core Systems Engineer (Paris, EU or US based). They develop the most secure wallet-as-a-service infrastructure in Web3 : an API-first wallet management system, ideal for applications and organizations seeking to provide secure access to all blockchains through a single integration ) . APIs and SDKs were designed for wallet programmability and efficient implementations, enabling fast deployments, smart automation flows, as well as granular sets of permissions and policies via secure authentication credentials. They are on the way to become the leading wallet infrastructure for the multi-trillion-dollar digital asset industry. The company is SOC-2 certified, employs 30 people across 6 countries and has raised over $20M since creation with prestigious investors. Their solution is used and trusted by major international corporations. They are looking for a Senior Core Systems Engineer to design, build and scale the systems at the heart of the company's platform: MPC, HSMs, TEEs, and the middleware that ties them together. You’ll work deep in the stack, building reliable distributed services and integrating them with cloud, hardware, and blockchain environments. This is a low-level, high-impact role where performance, security, and correctness are non-negotiable. You’ll design protocols, optimize databases, and harden workflows that power financial applications at scale. You’ll collaborate across product, research, and security to turn advanced cryptography into Rust-based, production-ready infrastructure that is fast, resilient, and trusted. MISSIONS Design, implement, and operate MPC signers, HSMs, and TEEs (e.g. AWS Nitro). Build low-level services and middleware in Rust and other systems languages. Architect distributed databases and stateful services for performance and reliability. Develop secure APIs and networking between core systems and high-level services. Optimize resource usage, latency, and throughput across critical workflows. Collaborate with cryptography, infra, and product to bring new protocols into production. Document core systems, share knowledge, and support client and partner discussions. Requirements 8+ years of systems engineering experience with focus on security, infra, or backend. Deep expertise in Rust, with strong low-level systems programming skills. Proven experience building distributed systems, consensus mechanisms, or networks. Hands-on experience with HSMs, MPC, TEEs, and cryptographic key management. Strong knowledge of SQL and NoSQL databases in high-availability environments. Familiarity with secure networking, applied cryptography, and defense-in-depth models. Skilled in observability, debugging, and optimizing performance at scale. Clear communicator, able to translate complex systems into practical solutions. Benefits Contract : Permanent role (Hybrid remote) in Paris (France) or other EU countries or US (EST times) Remote first company : flexibility to work fully remotely or at an office location of your preference within the European Union. Salary: 180 to 260k USD per year on a full-time permanent work contract. Equity: 100-200 stock options vested over 4 years with a one-year cliff. Work essentials: MacBook Pro, iPhone, AirPods, screens, headsets, AirPods, and cables are provided on Day 1 . Training and coursework in Crypto, Blockchain, Security, code, Coding languages and other topics are paid for on-demand to encourage personal and professional growth. Events: fully funded attendance at fintech, blockchain, or related conferences. Teams retreats/meetups/seminars/conferences all around the world to get to meet in-person and foster meaningful connections. Benefits: healthcare and life insurance, retirement plan, sponsored transportation, gym, lunch card, home office equipment, and other perks. Recruitment process : Video call with COO/CTO (30mn). Cognitive and personality tests (45mn). Take home Coding Test in language of your choice Gooup Focus interviews : code review/Architecture review/Security fundamentals/culture fit (30mn x 4). Final interview with Management.