Blockchain Developer (Java)

2 months ago

Remote, United StatesSenior

Responsibilities

Build and operationalize fault-tolerant, secure, scalable backend services for wallet operations, asset transfers, transaction orchestration, and blockchain integrations.
Develop API-first services integrating blockchain networks, third-party providers, and internal systems with strong consistency guarantees.
Implement cryptographic service communications, key management, zero-trust architecture principles, and secure transaction signing.
Build event-driven systems using Apache Kafka and asynchronous messaging patterns.
Develop highly available, strongly consistent, horizontally scalable, concurrent, and asynchronous services.
Integrate Web3 SDKs and libraries for on-chain interactions, transaction signing, and state monitoring.
Implement structured logging, distributed tracing, metrics, and OpenTelemetry instrumentation.
Maintain high automated unit, integration, and functional test coverage within CI/CD pipelines.
Create and maintain technical documentation, API specifications, and operational runbooks.

At least 7 years of software engineering experience building and operating production-grade backend systems in regulated financial or enterprise environments.
Experience with blockchain networks, smart contracts, consensus mechanisms, crypto integration, tokenization platforms, or related Web3 systems.
Extensive hands-on proficiency in Java and Spring Boot.
Ability to work across polyglot technology stacks.
Deep expertise in API-first design, RESTful service contracts, and microservices architecture patterns.
Strong command of concurrent, multithreaded, and asynchronous programming models.
Proven experience delivering highly available, strongly consistent, and distributed applications.
Hands-on experience building event-driven solutions with Apache Kafka.
Strong understanding of CI/CD, DevSecOps, secure SDLC, and automated security controls.
Hands-on experience with OpenTelemetry, distributed tracing, and observability platforms.
Strong technical writing skills and experience producing API specifications and operational runbooks.
Experience using Web3 libraries and SDKs such as Web3.js, Ethers.js, or equivalents.
Preferred experience with TypeScript, Node.js, NestJS, Ethereum, Bitcoin, Solana, XRPL, MPC, HSMs, enterprise key management systems, zero-trust security architecture, tokenization, stablecoins, settlement systems, digital asset operations, or open-source blockchain and Web3 tooling.

Remote work in the US.
Three-month initial B2B contract with the possibility of prolongation.
International experience with a stable technology company operating for more than 15 years.
Casual, positive, open, and innovative work environment.
Opportunities for personal and professional development and the chance to influence financial technology.

201-500 employees