Senior Backend / API Developer (Web3)

As a Senior Backend / API Developer at an innovative Web3 company, you will design, develop, and implement backend services and APIs that power solutions for supply chain verification, traceability, and digital integrity in transactional AI environments. You'll ensure applications and protocols deliver a seamless, secure, and efficient experience for users and clients through distributed ledger technology (DLT) and Web3.

What you'll do

• Design and develop scalable, efficient backend architectures for Web3 applications, ensuring high performance and availability.
• Implement and manage RESTful and GraphQL APIs that facilitate integration with DLT services and decentralized applications (dApps).
• Collaborate with frontend, DevOps, and security teams to create robust solutions that meet industry standards.
• Integrate third-party services such as oracles and decentralized storage protocols (for example, IPFS, Filecoin) into the application ecosystem.
• Optimise backend application performance and security through development best practices and agile methodologies.
• Participate in defining strategies for data management and storage, including information integrity and privacy.

What you bring

• A degree in Computer Science, Software Engineering, or a related field.
• Minimum 5 years of backend development experience, preferably in high-availability and high-performance environments.
• Solid experience with at least one of the following programming languages: Node.js, Python, Go, or Java.
• Experience developing and managing RESTful and GraphQL APIs.
• Knowledge of blockchain technologies, DLT, Web3 principles, and their application in software development.
• Experience with SQL and NoSQL databases, and data management in decentralized contexts.
• Backend application security best practices and identity management experience (DID, verifiable credentials).
• Professional level English; advanced Spanish is valued as the team is based in Spain.
• Based in Barcelona.

Nice to have

• Familiarity with modern Web3 frameworks and libraries such as ethers.js or web3.js.
• Experience implementing governance and compliance solutions in digital environments.
• Knowledge of containerisation and orchestration tools (Docker, Kubernetes).
• Experience implementing automated testing and CI/CD pipelines.

What we offer

• The opportunity to play a key role in developing innovative AI-driven solutions.
• A dynamic work environment with projects combining AI, governance, and advanced technology.
• Work flexibility, a competitive salary package, and the possibility of equity.

About Merlin Digital Partner

Merlin Digital Partner is a leading IT and digital recruitment consultancy with over 10 years of experience, having scaled major companies including Wallapop, Glovo, Banc Sabadell, and Sulzer. They focus on humanising and accelerating recruitment processes by deeply understanding each partner's needs and vision.