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Principal Software Engineer Dfns
Wallets-as-a-Service platform for secure digital asset management.
Permanent
Paris
Fully-remote
120K to 180K € a year
> 7 years
3 years of study
Skills we're looking for
Business acumen
Collaboration and teamwork
Problem-solving skills
Written and verbal communication
GraphQL
+7
You'll be part of
33 employees
Blockchain
Cyber Security
Finance
Average age: 38
Founded in 2020
85%
15%
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, 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.
You'll be working on
Join an exceptional team of leaders (CTO, CPO, Head of Research) and experts (Cryptography, Infrastructure, Security Engineers) to build the leading blockchain wallet infrastructure for the next financial era. We are hiring a Principal Software Engineer to develop and deliver high-quality software solutions. In this role, you will work with senior management to define requirements and lead key operational and technical projects. You will take ownership of critical projects and bring strong organizational and problem-solving skills to the team. As a Principal Software Engineer, you will also lead software change and release management, helping improve the software development process. Your goal will be to ensure software meets high-quality standards and is delivered on time.
We're looking for
Responsibilities
Share the team’s vision, set priorities on the product roadmap, and ensure deadlines and production quality are met.
Bring innovative ideas to solve technical challenges.
Apply best practices and promote innovation in development.
Improve work methods and processes to deliver on time.
Ensure the product is scalable, reliable, and built with high-quality code.
Troubleshoot and fix complex software issues effectively and permanently.
Review code based on functionality, speed, cost, and security requirements.
Collaborate with engineering, security, and product teams to turn feedback into actionable features.
Work with CISO to integrate security best practices into the architecture and workflows.
Respond quickly to problems, document fixes, and keep track of actions taken.
Create and update internal and external documentation.
Promote open communication and knowledge sharing within the team.
Stay informed about crypto and blockchain trends to guide the company’s strategy.
Research and recommend emerging technologies.
Occasionally join client meetings to explain how our solution compares to competitors.
Requirements
8+ years of experience as a Software Engineer or in a related role.
2+ years of experience in fintech or crypto, including blockchain work.
Bachelor’s degree or higher in computer science or similar field.
Proficient in Typescript and/or Rust (or similar languages).
Proven track record with developer tools, cybersecurity, infrastructure, and APIs.
Extensive experience designing and developing secure APIs (RESTful and GraphQL).
Skilled in evaluating and improving engineering decisions.
Writes unit, integration, end-to-end, and performance tests; practices chaos engineering.
Experienced in identifying and fixing performance bottlenecks.
Familiar with backend security, public key cryptography, hardware and firmware security, banking security models, encryption, and code vulnerabilities.
Strong knowledge of SQL (PostgreSQL) and NoSQL databases.
Hands-on experience with AWS services like Lambda, API Gateway, DynamoDB, S3, CloudFormation, and CloudWatch.
Skilled in building CI/CD pipelines, 12-Factor Apps, and domain-driven microservices.
Solid understanding of Functional, Object-Oriented, and Logic Programming.
Experience building observable systems with monitoring tools, including SIEMs.
Strong knowledge of algorithms and data structures.
Excellent problem-solving skills and ability to advocate for ideas.
Performs well under pressure with clear communication and decision-making.
Strong written and verbal communication skills.
Entrepreneurial mindset paired with professionalism.
Benefits
How we hire
Process
Intro call with Co-CEO (30 min).
Personality and cognitive tests (30 min).
Interview with CTO (30 min).
Coding test in a language of your choice.
Focus interview with hiring panel (90 min).
Reference calls and background checks.
Terms
Title: Principal Software Engineer
Salary: €120,000-180,000 per year (full-time work contract).
Equity: 300-900 stock options (i.e., 0.1-0.3%) vested over 4 years.
Location: France or EU (fully remote with optional access to office)
Equipment: MacBook Pro and other work essentials.
Key figures
In short
Founding year
2020
Employees
33
Average age
38
Gender
15%
85%
