Blockchain Java Backend Developer

Job Description

Blockchain Java Backend Developer

Must Have Technical/Functional Skills

Core Backend Skills

• Strong proficiency in Java (8+), and frameworks such as Spring Boot / Spring Cloud.
• Experience building distributed systems and microservices architectures at scale.
• Strong knowledge of:
• Concurrency, multithreading, asynchronous programming
• API design (REST/gRPC), security (OAuth2/JWT), and integration patterns
• Solid understanding of data stores:
• SQL (PostgreSQL/MySQL) and/or NoSQL (MongoDB/Cassandra)
• Caching (Redis) and search (Elasticsearch) is a plus
• Hands-on experience with message streaming/queues:
  
  

Blockchain Skills (Must-Have)

• Strong understanding of blockchain fundamentals:
• Transactions, blocks, confirmations/finality, consensus, gas/fees, wallets, keys.
• Experience integrating backend services with blockchain networks/nodes:
• Ethereum-compatible networks (Ethereum/Polygon/BSC) using Web3j, ethers-style approaches
• and/or permissioned chains (Hyperledger Fabric, Corda, Quorum)
• Experience supporting large blockchain deployments:
• Node connectivity, RPC management, event indexing, chain reorg handling, retry strategies.
  
  

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DevOps / Cloud (Preferred)

• Experience with Docker and Kubernetes for containerized microservices deployments.
• CI/CD exposure (Jenkins/GitHub Actions/GitLab CI/Azure DevOps).
• Cloud experience (Azure/AWS/GCP) is a plus.
• Understanding of security practices:
• Secrets management (Vault/KMS), TLS, RBAC, network security.
  
  

Roles & Responsibilities

• Design and develop Java-based backend services that interact with blockchain networks and nodes (public or permissioned).
• Build and scale microservices-based architecture supporting blockchain transaction workflows, event processing, and off-chain components.
• Develop reliable services for:
• Transaction orchestration
• Smart contract invocation
• Blockchain event subscription/listening
• On-chain/off-chain data synchronization
• Implement scalable APIs (REST/gRPC) for blockchain-enabled products and integrations.
• Optimize performance for high throughput and low latency:
• Transaction throughput handling, batching, retries, idempotency, rate limiting.
• Ensure secure integration with blockchain:
• Key management best practices, signing transactions, secure secret handling.
• Implement observability and reliability standards:
• Logging, monitoring, tracing, alerting, SLOs/SLAs.
• Work with DevOps/SRE teams to support production deployments, incident triage, and capacity planning.
• Contribute to architecture decisions including:
• Event-driven architecture (Kafka/RabbitMQ), caching strategies, database selection, and deployment topologies.
  
  

Salary Range- $100,000-$130,000 a year

Qualifications: BACHELOR OF COMPUTER SCIENCE