Blockchain Developer

Senior Blockchain Developer

Location: Warsaw

Contract Duration: 6 months (extendable)

Start Date: Immediate

Experience: 6+ years

About the Role:

We are looking for a Senior Blockchain Developer to join our team in Warsaw. This role involves developing scalable backend systems and blockchain-based solutions for innovative financial services projects. You’ll collaborate with a high-performing team and contribute to building secure, distributed applications that drive real-world impact.

Responsibilities:

• Design and develop scalable backend systems using Java, JavaScript, and Node.js.
• Build and integrate APIs, orchestration layers, and 3rd-party services, ensuring high availability and robust monitoring.
• Apply secure software development practices, including version control, CI/CD pipelines, unit testing, and performance testing.
• Develop solutions using blockchain technologies, including public and permissioned blockchains like Bitcoin, Ethereum, and Hyperledger.
• Contribute to the development of DeFi applications, secure private key custody systems, and distributed ledger solutions.
• Collaborate with product, compliance, and engineering teams to design systems for payment ecosystems and financial services.
• Continuously learn and adopt new technologies to address complex technical challenges.

Requirements:

• 5+ years of professional experience with a Bachelor's degree, or 4+ years with a Master's or other advanced degree.
• Strong programming skills in Java, JavaScript, and Node.js.
• Proven experience in building high-performing, distributed backend systems.
• Hands-on experience with blockchain technologies and decentralized applications.
• Knowledge of the secure software development lifecycle and associated best practices.
• Experience in financial services, payments ecosystems, or payment processing is a strong advantage.
• Strong interpersonal skills, with the ability to communicate complex ideas clearly and influence key stakeholders.
• A proactive, fast learner who thrives in a dynamic, collaborative environment.
• Full-stack development experience is a plus.