Crypto Developer

📍 Warsaw, Poland | Hybrid | B2B Contract | English-speaking environment

🌐 The Opportunity

Build blockchain and crypto products for a global payments technology leader whose platforms process real-time transactions for millions of businesses and consumers worldwide. This role suits a senior engineer who wants to work at genuine global scale, where security, resilience and performance are non-negotiable.

🛠 What You'll Do

• Design, build and maintain enterprise-grade crypto and blockchain products

• Develop scalable distributed systems: APIs, orchestration layers and third-party integrations

• Build and enhance backend services in Java, collaborating with frontend teams on Angular

• Own delivery end-to-end, from architecture and design through deployment and production support

• Drive monitoring, alerting and high availability for mission-critical services

• Implement CI/CD pipelines, testing frameworks and secure engineering standards

✅ What You'll Bring

• 12+ years' experience with a Bachelor's degree, or 8+ years with an advanced degree (Master's, MBA, etc.)

• Strong background building high-performance distributed systems and APIs

• Deep knowledge of blockchain technologies: public and permissioned chains, DeFi, distributed ledgers (Bitcoin, Ethereum, Hyperledger)

• Hands-on Solidity, EVM and Assembly experience

• Solid grasp of security protocols and private key custody

• Full Secure SDLC experience: version control, CI/CD, unit and performance testing

⭐ Strongly Preferred

• Full-stack experience: Java backend + Angular frontend

• Payments, fintech or financial services domain knowledge, including compliance and payment processing flows

💡 Why Join

• Work on payments infrastructure used worldwide every day, where milliseconds matter

• Build blockchain products inside a global financial leader, a rare combination on any CV

• Collaborate with senior international engineering teams in a hybrid Warsaw setup

👉 Apply now. Shortlisted candidates will hear from our team within 48 hours.