Senior Blockchain Platform Engineer [AQ-12196]

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 is a hands-on role where you will design, build, and scale foundational blockchain and tokenization infrastructure, transitioning from prototypes to secure, scalable, and production-ready systems. Your work will directly influence the strategic direction of emerging technology, enabling new capabilities across smart contracts, token lifecycle services, blockchain connectivity, and sophisticated distributed systems.

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.

Preferred Qualifications

• 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 get access to amazing benefits, including:

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