Senior Backend Developer

About the role

expand.network is looking for a Senior Backend Developer to build and scale the core API that powers a unified DeFi data platform. You will work on high‑performance services that enable clients to access real‑time and historical on‑chain data across dozens of protocols.

Key responsibilities

• Design, develop, and maintain scalable backend services using Node.js, the MERN stack, Python, Git and cloud infrastructure.
• Implement secure, performant APIs (REST and WebSocket) for Web3 and DeFi applications.
• Architect and optimise NoSQL database schemas for data integrity and speed.
• Write clean, modular, well‑documented code and participate in code reviews.
• Troubleshoot, debug and optimise application performance.
• Stay up‑to‑date with the latest trends in blockchain, DeFi and web3 technologies.

Required profile

• Proven experience as a senior backend developer with deep expertise in Node.js and the MERN stack.
• Strong understanding of blockchain technology and DeFi protocols.
• Experience building RESTful APIs and WebSocket services.
• Solid knowledge of security best practices for backend applications.
• Ability to work in a fast‑paced, remote‑first environment and collaborate effectively.

Required skills

• Node.js
• MERN stack
• Python
• Git
• AWS, Azure or Google Cloud
• NoSQL databases
• RESTful API design
• WebSocket programming
• Docker
• Kubernetes
• CI/CD pipelines
• DevOps practices
• Solidity and smart‑contract development (nice to have)
• Go, Rust (nice to have)

What we offer

• Competitive salary and equity options.
• Flexible working hours and remote work opportunities.
• Chance to work on cutting‑edge web3 and DeFi projects.
• Professional growth and development in a collaborative, inclusive environment.