Senior Blockchain Engineer

Context

Dfns is a cybersecurity company that builds custody SaaS protocol for web3 apps. Think of it as a developer tool that provides secure cloud for crypto. Our mission is to bring serenity to DeFi by eliminating new blockchain risks and making crypto transactions easier, faster, more affordable, and compliant with existing regulations.

From fintechs to large banks to e-commerce sites, Dfns gives financial institutions and businesses the freedom to own and transfer crypto on a battle-designed security infrastructure. Our API is designed to offer best-in-class developer experience allowing any platform to deploy custodial wallets in a matter of days, with streamlined feature delivery and frequent security upgrades.

Founded in 2020 in Paris, Dfns is a startup incubated at Station F (awarded Future 40), accelerated by Techstars and recognized DeepTech by the French Ministry of Economy. Our company is fully remote with offices in Paris, Amsterdam, New York, London, Stockholm, Sofia, and other cities.

Job Description

You will contribute to one of the most ambitious technology projects in crypto today: building a trustless custody infrastructure for the trillion-dollar digital asset industry.

You will join an amazing team of leaders (CTO, CPO, VP of Research) and experts (R&D Engineers, Software Engineers, Security Engineers) in a highly challenging and collaborative environment.

We are looking for a highly capable Senior Blockchain Engineer to design, implement, and distribute a secure blockchain-based network. You will be analyzing our blockchain needs and designing customized blockchain strategies. To ensure success, you must understand the mechanics of blockchains like Bitcoin, Ethereum, Solana and other popular public blockchains, and possess extensive knowledge of programming languages like Rust, Go, Python, and crypto-systems.

As a Blockchain Engineer, you must act as a complete package who can perform the operations, design, development, analysis, implementation, and support of a distributed blockchain network. We are searching for someone who can, not only work with blockchains, but also invent new routes for a trustless decentralized crypto custody solution by exploring the use of blockchains.

Mission

Your primary goal will be to contribute to researching ways to decentralize the company and its products, and make them trustless by using or creating a best-for-purpose blockchain.

Example of a primary metric would be WTL (Weeks to Launch).

Your day-to-day projects will involve:

• Sharing the big picture to your team, defining the levels of priority within the product roadmap, and being accountable for the deadlines and the quality of production.
• Acting as a powerhouse of ideas on all technical issues.
• Ensuring scalability and high availability of the product, as well as top-notch code quality.
• Building, operating, and ensuring the security of the product, namely the blockchain.
• Implementing an MPC-based crypto-system with the assistance of our R&D team.
• Evaluating product code according to specifications, and gathering product requirements (e.g. functionalities, speed, safety standards)
• Collaborating with managers to determine blockchain technology needs and envisaged functionalities.
• Designing, developing, testing and troubleshooting apps using blockchain technology.
• Maintaining, updating, and integrating to new blockchains in a systematic way.
• Authoring and updating internal and external documentation.
• Facilitating cross-team communication and know-how exchange between team members.
• Implementing technical best practices and new ideas to encourage innovation within your team.
• Working closely with CISO to embed best-in-class information security processes within the service architecture and the internal workflows.
• Working closely with the Head of Legal and the compliance team in charge of crunching our legal requirements to translate the product evolutions into features that take into account jurisdictional constraints and regulatory frameworks.
• Keeping abreast of the latest developments in crypto, DeFi and blockchain to feed the company's strategic orientations.
• Continually researching current and emerging technologies and propose changes.
• Educating all teams on blockchain features that allow secure digital payments.

Requirements

• 6+ years experience as a Software Engineer, of which 3+ as a Blockchain Engineer
• In-depth understanding of languages, like Rust, Go, Python, and/or Typescript.
• Engineering expert capabilities of challenging the reasoning of other engineers.
• Experience in writing Unit tests, Integration tests, End-to-end tests, performance tests, and chaos engineering.
• Knowledgeable with SQL (PostgreSQL) and NoSQL databases.
• Experience with cloud platforms such as AWS, GCP, and setting up environments between them.
• Experience building CI/CD pipelines, 12-Factor App, and domain-driven microservices.
• Experience with Infrastructure as a Code platforms like Terraform.
• Understanding of Functional Programming, Object-Oriented, and Logical Programming.
• Experience in building observable systems with Datadog, Splunk, etc.
• Good understanding of cryptography and peer to peer networks.
• Experience testing secure, fault-tolerant, and resilient systems.
• Practical experience generating process documentation and reports.
• Excellent written and verbal communication skills.
• Excellent analytical and problem-solving skills.
• Founding-spirited with grit and guts to pursue complex worldwide ambitions.
• Humble, respectful, and very professional to others.
• Able to decide even in stressful, unstable situations.
• Appetite for Cybersecurity, Fintech, Blockchain and/or Crypto industries.
• [Bonus] Hands-on experience and willingness to contribute to open source projects.
• [Bonus] Proven track record working on developer tools, cybersecurity software, infrastructure products, and/or API products.
• [Bonus] Proven work experience in blockchain, DeFi and/or cybersecurity industries.
• [Bonus] Extensive knowledge about the crypto custody industry and its use cases.

Benefits

• Title: Senior Blockchain Engineer
• Salary: €120-250K / year (avg base range).
• Equity: 0.2-0.4% (≈ €7.2-14.4M in case of €2B exit).
• Bonus: Peer and spot bonuses after 8 months with us.
• Location: Hybrid. You can either work in our offices, from home, or remote.
• Paid time off: No less than 30 days per year, plus national holidays.
• Employee benefits: healthcare, life insurance, retirement plan, sponsored transportation, gym cards, food, Apple devices and home office equipment, tuition fee assistance, team retreats, and more.