Junior/Mid Full Stack Developer

Founded in Paris in 2014, Ledger is the global leader in digital asset security and Web3 infrastructure. With over 7 million devices sold across 180+ countries, Ledger secures 20% of the world's crypto assets. A team of 600+ professionals works across distributed teams worldwide, with headquarters in Paris. Beyond hardware, Ledger actively supports the broader blockchain and crypto ecosystem through its developer platform and global partnerships.

About the Role

We're looking for a Full Stack Developer with a backend focus to join Ledger's Partner Integration team on a contract basis. This team sits at the heart of the Ledger Wallet application — responsible for integrating third-party crypto providers (onramp/offramp, swap, staking) through extensive API connectivity, service monitoring, and custom integration development.

You'll work closely with the team lead and collaborate cross-functionally with product, data, and engineering teams. The role offers a 360° view of the crypto product landscape — you'll be touching everything from buy/sell flows to staking integrations, working on things that real users interact with every day.

This is a great fit for someone who genuinely loves crypto and wants to see the direct impact of their work.

What You'll Do

• Build and maintain backend integrations with third-party crypto providers (onramp/offramp, swap, staking)
• Develop and monitor API connections, ensuring reliability and performance
• Occasionally contribute to frontend maintenance tasks
• Collaborate with internal tech, product, and data teams across the organization

What We're Looking For

• 2–3 years of backend development experience
• Hands-on experience with Scala, Java, Kotlin, or a comparable backend language — willingness to work in Scala is key
• Familiarity with TypeScript is a plus (frontend tasks will be light)
• Solid understanding of Git and CI/CD practices
• Genuine knowledge of the blockchain/crypto ecosystem — professional experience is a plus but not required; passion and active engagement in the space are equally valued
• API integration experience is a nice-to-have, not a hard requirement