Senior Software Architect, Blockchain & DeFi

Ledger; Paris; Hybride; EUR 80 000 - 110 000; Plein temps

Résumé du poste

A leading digital asset firm in Paris seeks a Technical Architect to join its Engineering Architecture team. The role involves leading the design and integration of blockchain protocols and supporting engineering teams in delivering high-reliability services. Ideal candidates will have over 10 years of experience, deep expertise in backend architecture, and a strong understanding of blockchain technologies. Flexible work options and comprehensive benefits are part of the package.

Prestations

Flexible work options

Health & Wellness support

Financial growth opportunities

Commuter allowance

Learning & Development programs

Qualifications

• 10+ years of experience in technical design, development, execution, and delivery.
• Deep expertise in backend system architecture for high-reliability services.
• Hands-on knowledge of blockchain technologies and complex systems.

Responsabilités

• Lead technical design for integrating new blockchain protocols into Ledger.
• Collaborate closely with product and engineering teams for quality assurance.
• Contribute hands-on to development activities for supported teams.

Connaissances

Backend system architecture

High-throughput transactional services

Blockchain technologies

Cross-functional teamwork

Presentation and communication

Formation

Engineering degree

Outils

Node.js

Python

Scala

SQL

NoSQL

Description du poste

About Ledger

We’re a team of experts pushing the limits of what’s possible, united by our common goal to unlock true freedom through digital ownership, making technology accessible for all. We believe in a world where users, creators and enterprises manage their value with ownership and freedom. Our curiosity drives us to innovate, empowering individuals on a global scale. We believe change is constant and our team moves forward as one, with a culture of problem‑solving where every employee is empowered and supported to challenge tradition and create solutions. Our mission is simple: to make self‑custody accessible and give people the keys to their own financial futures. If you want to make a true impact, we want you to join us at Ledger.

At Ledger, we’re proud to be the global platform for digital assets and Web3, with over 20% of the world’s crypto assets secured through our Ledger devices. With our headquarters in Paris, and offices in Vierzon, Grenoble, Montpellier, London, Portland, Geneva, Zurich and Central Singapore, we have a team of around 600 professionals developing a variety of products and services to enable individuals and companies to securely buy, store, swap, grow and manage crypto assets – including the Ledger hardware wallets line with more than 7.5 million units already sold in 200 countries.

The team

As part of a strong growth we are looking for talent to join the Engineering Architecture team. The architecture team is responsible for ensuring the highest level of design quality for both our B2C and B2B products, as well as helping the Product teams scope and build the next great features of our products.

The architecture team aims at building deep, specialized expertise in Ledger's transactional services, and in this context we are looking at reinforcing our team with a future expert to drive the architecture, integration, and improvement of our core services, with a strong focus on new Blockchain protocols and Decentralized Finance (DeFi) applications.

This is a hands‑on position and we expect our architects to be able to dig deep into the code and help engineering teams in their day to day issues.

Team missions

• Support Product & Engineering on Discovery & Design of new product features
• Drive Tech Initiatives with Engineering to improve our stack, address tech debt and support good engineering practices
• Support engineering teams on critical topics by providing expertise and hands‑on contribution to engineering squads
• Explore new, innovative domains with a focus on concrete Ledger applications, particularly in the Web3/DeFi space

What you’ll be doing

The responsibilities of an architect are mostly geared toward the engineering teams they support:

• Lead the technical scoping, design, and architecture for integrating new blockchain protocols and tokens into the Ledger ecosystem.
• Drive the research, understanding, and integration of complex Decentralized Finance (DeFi) protocols (e.g., DEXs, lending, staking) with Ledger services, ensuring security and scalability.
• Collaborate closely with engineering leads, product managers and delivery managers to ensure design on most important initiatives are properly done and of good quality.
• Partner with product teams to define, develop and implement development requirements for new product features.
• Help Engineering managers identify, tackle and prioritize most critical technical debt in our transactional services stack.
• Contribute hands‑on to the development activities of the squads being supported.
• Become a Ledger solution expert to thoroughly understand all use‑case scenarios, especially on areas identified in this job description.

An architect is also responsible for some transversal activities, including:

• Be involved in our open source projects and foster our developer community by contributing and maintaining key Open Source software, and helping build our platform strategy.
• Help build visibility on the roadmap by contributing to gross estimates of implementation difficulty.
• Help contribute to Ledger visibility by presenting in conferences or in front of customers our technology know‑how.

What we’re looking for

Requirements

• 10+ years of experience in technical design, development, execution, testing and delivery.
• Deep expertise/interest in backend system architecture, algorithm development, and optimization for high‑throughput, high‑reliability transactional services.
• Profound, hands‑on knowledge of how various blockchain technologies (e.g., Ethereum, EVMs, non‑EVMs) work under the hood, and a curiosity to investigate deeply complex, distributed systems.
• Ability to work effectively with internal teams to define scope, goals, project plans and deliverables.
• Team player with excellent interpersonal skills and ability to work cross‑functionally.
• Excellent presentation and written communication.
• Engineering degree.

Requirements based on target engineering team

• Expert knowledge of backend development and architecting scalable, secure web services (e.g., Node.js, Python, Scala).
• Experience with advanced software development practices and patterns for distributed, fault‑tolerant systems.
• Deep understanding of smart contract security, token standards (ERC‑20, ERC‑721, etc.), and the architecture of common DeFi primitives (DEXs, Lending Protocols, Yield Farming).
• Practical experience with blockchain node interaction (RPC, WebSockets) and building robust, high‑availability data indexing and transaction services.
• Strong knowledge of database technologies (SQL/NoSQL) and message queues for asynchronous data processing in backend systems.

Nice to have

• Open source experience or contributions, especially in the blockchain/crypto space.
• Expert knowledge of cryptography and security practices applied to transactional systems.
• Prior experience contributing to or integrating with major DeFi protocols.

At Ledger, we are dedicated to continually investing in our employees which is why we offer more than just salaries; we provide comprehensive compensation packages that include a wide range of benefits. Here are some of the benefits you can look forward to:

• Flexible work options – Our hybrid policy allows employees to work from home up to 3 times per week
• Health & Wellness support – Health and Life Insurance.
• Financial growth opportunities – Employees can become shareholders in Ledger as well as other financial benefits depending on your country of work.
• Commuter allowance – Ledger offers a commuter allowance to contribute to your preferred means of transportation.
• Learning & Development – A comprehensive suite of training solutions providing a personalised learning experience for every employee.

For regionally specific benefits, your Talent Acquisition contact will be able to provide you with more information.

We’re committed to building an inclusive hiring process. If you need any adjustments or accommodations, just let us know, we’ll do our best to support you.