Blockchain Java Backend Engineer

New York City, NY - USA

Monthly Salary: Not Disclosed

Posted on: Yesterday

Vacancies: 1 Vacancy

Job Summary

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:

o Concurrency multithreading asynchronous programming

o API design (REST/gRPC) security (OAuth2/JWT) and integration patterns

Solid understanding of data stores:

o SQL (PostgreSQL/MySQL) and/or NoSQL (MongoDB/Cassandra)

o Caching (Redis) and search (Elasticsearch) is a plus

Hands-on experience with message streaming/queues:

Blockchain Skills (Must-Have)

Strong understanding of blockchain fundamentals:

o Transactions blocks confirmations/finality consensus gas/fees wallets keys.

Experience integrating backend services with blockchain networks/nodes:

o Ethereum-compatible networks (Ethereum/Polygon/BSC) using Web3j ethers-style approaches

o and/or permissioned chains (Hyperledger Fabric Corda Quorum)

Experience supporting large blockchain deployments:

o Node connectivity RPC management event indexing chain reorg handling retry strategies.

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:

o 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:

o Transaction orchestration

o Smart contract invocation

o Blockchain event subscription/listening

o 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:

o Transaction throughput handling batching retries idempotency rate limiting.

Ensure secure integration with blockchain:

o Key management best practices signing transactions secure secret handling.

Implement observability and reliability standards:

o 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:

o Event-driven architecture (Kafka/RabbitMQ) caching strategies database selection and deployment topologies.

Salary Range: $100000 to $130000 per year

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: o Concurrency multithreading asynchronous...