Blockchain Developer (Java)

Accountabilities

• • Design, implement, and operate core backend services with a strong focus on fault tolerance, security, scalability, and reliability.
  • Build API-first services that integrate blockchain networks, third-party providers, and internal platforms while maintaining strong consistency and well-defined service contracts.
  • Develop secure service-to-service communication using cryptographic signatures, key management practices, and Zero Trust architecture principles.
  • Build and maintain event-driven architectures using Apache Kafka and asynchronous messaging patterns.
  • Develop highly available, strongly consistent, horizontally scalable distributed services capable of supporting production workloads.
  • Implement robust concurrent and asynchronous processing models for multi-threaded and high-throughput applications.
  • Integrate Web3 SDKs and libraries to support on-chain interactions, transaction signing, blockchain state monitoring, and related workflows.
  • Contribute to blockchain integrations involving wallets, digital assets, transaction processing, and distributed ledger technologies.
  • Implement structured logging, distributed tracing, metrics, and OpenTelemetry instrumentation to maintain strong system observability.
  • Develop and maintain comprehensive automated unit, integration, and functional testing within CI/CD pipelines to ensure production quality.
  • Apply secure SDLC, DevSecOps, and automated security practices throughout the software development lifecycle.
  • Produce and maintain technical documentation, API specifications, operational runbooks, and other engineering documentation.
  • Contribute to architectural decisions and continuously improve the reliability, security, and scalability of backend systems.

  Requirements

  • 7+ years of professional software engineering experience building and operating production-grade backend systems, preferably within regulated financial services or enterprise environments.
  • Demonstrated experience with blockchain networks, smart contracts, consensus mechanisms, cryptocurrency integrations, tokenization platforms, or related Web3 technologies.
  • Extensive hands-on experience with Java and Spring Boot, with the ability to work comfortably across polyglot technology stacks.
  • Strong expertise in API-first architecture, RESTful service design, microservices, and distributed application patterns.
  • Advanced understanding of concurrent, multi-threaded, and asynchronous programming models.
  • Proven experience designing and delivering highly available, strongly consistent, and horizontally scalable distributed systems.
  • Hands-on experience developing event-driven applications with Apache Kafka and asynchronous messaging.
  • Strong understanding of CI/CD pipelines, DevSecOps, secure SDLC practices, and automated security controls.
  • Experience with OpenTelemetry, distributed tracing, metrics, logging, and modern observability platforms.
  • Proven ability to use Web3 libraries and SDKs such as Web3.js, Ethers.js, or equivalent technologies.
  • Strong technical writing skills, including experience creating API specifications, technical documentation, and operational runbooks.
  • Experience with TypeScript, Node.js, or NestJS is a plus.
  • Familiarity with Ethereum, Bitcoin, Solana, XRPL, or other distributed ledger technologies is highly desirable.
  • Knowledge of MPC, HSMs, enterprise key management, and Zero Trust security architectures is advantageous.
  • Understanding of tokenization, stablecoins, settlement systems, and digital asset operations is a plus.
  • Contributions to open-source blockchain projects or Web3 tooling are valued.
  • Strong analytical and problem-solving abilities, with the capacity to work effectively on complex technical challenges in a collaborative environment.

  Benefits

  • Initial 3-month B2B contract with the possibility of extension.
  • Remote position based in the United States.
  • Opportunity to work on complex blockchain, Web3, and digital asset technology within financial services.
  • International exposure through collaboration with a globally distributed technology organization.
  • Innovative, open, and collaborative working environment.
  • Opportunities for personal and professional development.
  • Opportunity to contribute to projects that are shaping modern financial technology and digital asset infrastructure.