Senior Blockchain Engineer

About

Dfns is the leading Wallets-as-a-Service (WaaS) platform, helping fintechs, institutions, and enterprises simplify digital asset management and securely onboard users onchain.

Its API-first wallet platform unifies transaction management, workflow governance, key deployment, and third-party integrations into one secure operating system for blockchains. Built on advanced security and cryptography, Dfns is trusted by over 200 financial institutions and applications—including ABN AMRO, Broadridge, Fidelity, Zodia Custody, Banca Sella, Stripe, Moonpay, Circle, IBM, Deblock, and Gemini—and secures over $3 billion in monthly transactions.

Founded in 2020, Dfns has raised $30 million from global investors such as White Star Capital, Motive Partners, Bpifrance, Coinbase, Wintermute, and Susquehanna. Originally incubated by Techstars and Station F in Paris, Dfns now operates globally with teams across the US, Europe, the Middle East, and Asia.

Job Description

Join a stellar team of leaders and experts in blockchain technology, cryptography, infrastructure, and security to build the backbone of blockchain wallet infrastructure for the next financial era. We’re hiring a Senior Blockchain Engineer to design, develop, and scale the components that connect our platform to every blockchain network. You’ll work on indexing, data pipelines, and integrations across major networks, while also building smart contracts and analysis tools that make our wallet platform faster, more reliable, and easier to integrate. This role is both hands-on and strategic: you’ll improve our blockchain services, our indexing and monitoring infrastructure, and ensure our integrations remain secure and resilient under real-world financial workloads.

Preferred Experience

Responsibilities

  • Design and implement blockchain indexers, data pipelines, and integrations.

  • Develop and maintain smart contracts with a focus on security and performance.

  • Build APIs and services that expose onchain data for wallets and financial apps.

  • Troubleshoot indexing issues, resolve performance bottlenecks, and ensure reliability.

  • Collaborate with product and research to prioritize new blockchain integrations.

  • Contribute to CI/CD, monitoring, and observability for blockchain services.

  • Document systems, share knowledge, and support technical discussions with partners.

Requirements

  • 8+ years of software engineering experience, with 2+ in blockchain development.

  • Strong in TypeScript, plus ideally one systems language (Rust, Go, C++).

  • Proven experience building blockchain indexers, explorers, or related tooling.

  • Skilled in designing and auditing smart contracts (EVM and non-EVM a plus).

  • Familiar with multiple blockchain ecosystems, both public (Ethereum, Solana, Cosmos, etc.) and private (Besu, Canton, R3 Corda, etc.).

  • Expertise with databases (PostgreSQL, DynamoDB, NoSQL) and data pipelines.

  • Strong understanding of blockchain security, cryptography, and consensus models.

  • Clear communicator with experience collaborating across product and infrastructure.

Recruitment Process

Process

  • Intro call with Co-CEO (30 min).

  • Personality and cognitive tests (45 min)

  • Coding test in a language of your choice.

  • Focus interviews with the hiring panel (180 min).

    • Code review
    • Architecture review
    • Security fundamentals
    • Culture check fit

  • Final interview with CTO (30 min).

  • Reference calls and background checks.

Terms

  • Title: Senior Blockchain Engineer

  • Salary: $160,000–240,000 per year (full-time)

  • Equity: 150–300 stock options vested over 4 years

  • Benefits: Healthcare, 401K, and travel expenses

  • Location: US or EU (remote-first, office optional)

  • Equipment: MacBook Pro + essentials

Additional Information

  • Contract Type: Full-Time
  • Location: Paris, New York
  • Experience: > 7 years
  • Possible full remote
  • Salary: between 160000$ and 240000$ / year
Apply Now

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