Lead Backend Developer - Blockchain Platform

About the Position

We are seeking a Lead Backend Developer for a blockchain platform to drive the development of enterprise-grade backend services. The role involves blockchain integrations and financial services requirements.

Responsibilities

• Lead development of backend services for stablecoin lifecycle management (issuance, redemption, freezing, audit) with smart contract interactions and role-based access control
• Oversee custodial wallet backend development with an understanding of various wallet architectures: custodial, multisig, MPC, and account abstraction concepts
• Drive crypto-acquiring platform backend development, including merchant onboarding, POS integrations, transaction processing, and settlement workflows
• Develop blockchain integrations using web3j for Ethereum/Besu and smart contract interactions across all platform tracks
• Implement RESTful APIs and gRPC services for internal and external system integrations, including banking systems and mobile applications
• Coordinate with mobile development teams for banking application integrations and API design
• Build secure key management and signing services integrated with HSM, MPC solutions, and keyless architectures
• Optimize backend performance for high-throughput transaction processing across all platform components
• Lead and mentor the development team, ensuring code quality standards and best practices across multiple tracks

Requirements

• Extensive backend development experience with a significant background in blockchain/cryptocurrency projects
• Strong proficiency in Java (Spring Boot) and enterprise backend development
• Hands-on experience with Web3J or similar blockchain integration libraries
• Deep understanding of blockchain concepts: EVM, transactions, gas optimization, smart contract interactions
• Understanding of different wallet architectures and custody models
• Experience with smart contract development, role-based access control, and tokenization systems
• Knowledge of payment processing, POS integrations, and acquiring systems
• Strong experience with microservices architecture, API design, and enterprise integration patterns
• Experience with mobile application backend development and API design for mobile clients (e.g., using languages such as Java, Go, etc.)
• Proficiency in database design and optimization (PostgreSQL, MongoDB, Redis)
• Experience leading development teams and mentoring junior developers
• English proficiency at B2 level or higher

Nice to Have

• Experience with Hyperledger Besu or enterprise blockchain platforms
• Experience with backend development for mobile applications in Go as an example, as well as knowledge of publishing mobile apps to app stores and navigating app store submission procedures
• Knowledge of HSM integration, hardware security modules, and MPC implementations
• Experience with account abstraction implementations and keyless wallet architectures
• Experience with POS systems and payment terminal integrations
• Understanding of financial regulations and compliance requirements for digital assets
• Experience with high-throughput financial systems and payment processing

We Offer

• Diverse multicultural, multi-functional, and multilingual work environment
• Global scope, international projects in different business domains: life sciences and healthcare, retail, and distribution, software and hi-tech, etc.
• Outstanding career development opportunities with a transparent career path and a roadmap to accelerate your journey
• Great learning and development opportunities, including in-house professional training, career advisory and coaching, sponsored professional certifications
• Knowledge-sharing with colleagues from EPAM's global tech communities
• 25 days holiday per annum
• 5 days of sick leave without medical certification
• Private health insurance for employees and discount for private health insurance for family members
• Discount for Fit Pass program
• Comfortable modern offices in Belgrade and Novi Sad or remote work from any location in Serbia
• Regular corporate, social and wellbeing events (parties, sport events, advanced CSR programs etc.)

About the Company

[Company description if present]