Lead Backend Developer - Blockchain Platform

We are looking for an experienced Lead Backend Developer to drive the development of enterprise-grade backend services for a comprehensive blockchain platform. You'll lead backend development across three key tracks: stablecoin infrastructure, custodial wallet systems, and crypto-acquiring platform, with a focus on blockchain integrations and financial services requirements. Thank you for your interest in this position. Please note that only candidates whose experience closely matches the job requirements will be contacted. If you do not receive an email from us, please do not be discouraged—feel free to apply for other positions that better align with your experience. If you have any questions, you can reach us at jobserbia@epam.com 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