Senior Blockchain Platform Engineer [AQ-12983]

About the Role

Aquent Talent is partnering with a pioneering financial services institution at the forefront of innovation, dedicated to shaping the future of finance through cutting-edge technology. This role offers the opportunity to design, build, and scale foundational blockchain and tokenization infrastructure that will power the institution’s operations. You will architect solutions and transition them from prototypes to secure, scalable, and production-ready systems, directly influencing the strategic direction of emerging technology in decentralized finance.

Responsibilities

• Design and build reusable Web3 platform services for tokenization, transaction processing, blockchain connectivity, wallet integration, event ingestion, indexing, and token lifecycle management.
• Develop backend services that interact with blockchain nodes, smart contracts, signing systems, custody platforms, and off-chain systems.
• Create common blockchain abstraction layers to support multiple networks, including enterprise implementations, distributed ledger technology frameworks, Layer 2 networks, permissioned chains, and future enterprise blockchain platforms.
• Build integrations with enterprise implementations, compatible networks, and permissioned chains.
• Implement blockchain connectivity using JSON-RPC, WebSocket subscriptions, ABI encoding/decoding, event logs, transaction submission, transaction status tracking, and smart-contract queries.
• Support engineering patterns for specific distributed ledger technology frameworks, including validator or participant connectivity, application package lifecycle, transaction authorization, and workflow integration.
• Work with application concepts for distributed ledger platforms, including package deployment, versioning, installation validation, and application enablement.
• Build or integrate services that support institutional transaction authorization, wallet integration, and node connectivity for enterprise distributed ledger technology workflows.
• Partner with platform, infrastructure, and operations teams to evaluate validator strategies for enterprise distributed ledger technology networks, including self-hosted and provider-operated models.
• Design, develop, integrate, and review smart contracts for tokenized asset and programmable workflow use cases.
• Work with Solidity, token standards, upgradeable contracts, proxy patterns, access-control models, permissioned-token designs, and contract event models.
• Build smart-contract interaction layers that manage ABI encoding, calldata construction, transaction simulation, event decoding, and contract state reads.
• Establish engineering standards for smart-contract development, testing, deployment, versioning, rollback planning, and production change governance.
• Support smart-contract security practices, including threat modeling, static analysis, fuzzing, invariant testing, and secure deployment pipelines.
• Integrate with institutional wallet, custody, signing, and authorization platforms that support tokenized asset workflows.
• Design transaction orchestration workflows covering request validation, policy checks, approval routing, signing, submission, confirmation tracking, retries, exception handling, and audit logging.
• Support address or account registration, transaction limits, allowlists, signing policies, approval workflows, and operational controls.

Requirements

• 5+ years of software engineering experience building distributed systems, backend platforms, financial systems, blockchain infrastructure, custody platforms, trading systems, or high-scale transaction systems.
• Strong hands-on Web3 engineering experience.
• Deep understanding of blockchain protocols, including smart contracts, ABI encoding, transaction lifecycle, gas/fee handling, nonce management, logs/events, confirmations, and finality.
• Experience building backend services that interact with blockchain nodes, wallets, smart contracts, signing systems, or custody platforms.
• Experience with JSON-RPC, WebSocket subscriptions, blockchain event indexing, smart-contract integration, transaction monitoring, and blockchain data models.
• Strong understanding of wallet infrastructure, transaction signing, address management, custody concepts, and key-management patterns.
• Strong backend engineering skills in one or more languages such as Java, Go, Kotlin, TypeScript, Rust, Python, or C++.
• Experience with APIs, microservices, event-driven architecture, messaging systems, cloud-native engineering, and production operations.
• Ability to independently own complex engineering problems from design through production delivery.
• Experience with specific distributed ledger technology frameworks, their application models, validator/participant concepts, application package deployment, or institutional blockchain workflows.

Nice to Have

• Experience with enterprise blockchain implementations, permissioned networks, or private blockchain deployments.
• Experience with smart-contract audits, fuzz testing, invariant testing, static analysis, formal verification, or secure smart-contract deployment.
• Experience building blockchain indexers, transaction orchestration systems, custody integrations, token lifecycle platforms, or wallet-policy engines.
• Experience with token standards such as ERC-20, ERC-721, ERC-1155, ERC-1400, ERC-3643, or other permissioned-token frameworks.
• Experience building systems in regulated, security-sensitive, or high-value transaction environments.
• Relevant blockchain certifications or training, including certifications in enterprise blockchain platforms or distributed ledger technologies.

Benefits

Eligible talent at Aquent Talent gain access to:

• Subsidized health, vision, and dental plans.
• Paid sick leave.
• Retirement plans with a company match.
• Free online training through Aquent Gymnasium.