21 hours ago
Responsibilities
- Build and maintain wallet infrastructure for key management, transaction signing, and orchestration across custodial and programmatic wallets.
- Implement on-chain transaction handling across EVM and other supported networks, including gas, nonce management, retries, confirmation tracking, and failure recovery.
- Develop stablecoin minting, burning, and settlement logic connecting USDC and other stablecoins to fiat on-ramp and off-ramp products.
- Build integrations with centralized and decentralized exchanges, liquidity-routing systems, and cross-chain bridges.
- Create and maintain a double-entry ledger with automated reconciliation across on-chain balances, banking partners, and customer accounts.
- Develop event listeners, webhooks, screening hooks, and idempotent transaction pipelines that provide reliable visibility and transaction processing.
- Partner with engineering, product, and compliance teams to evaluate new chains and protocols and implement controls such as wallet screening and transaction monitoring.
Requirements
- 3+ years of software engineering experience, including 1–2 years building blockchain systems in production.
- Deep familiarity with EVM chains, transaction lifecycles, gas mechanics, common failure modes, and enough Solidity to read and integrate smart contracts.
- Experience with wallet architecture, including custody models, signing services, or MPC- and HSM-backed setups.
- Strong backend fundamentals in API design, data modeling, and consistency and concurrency in distributed systems.
- Experience building financial systems with reconciliation and audit trails.
- Clear communication in code reviews and writing.
- Preferred: experience with stablecoin infrastructure such as Circle or on-chain and fiat settlement.
- Preferred: hands-on experience with CEX APIs, DEX protocols such as Uniswap, bridge integrations, ledgers, double-entry accounting systems, compliance engineering, non-EVM chains such as Solana or Tron, ACH, wires, traditional money movement, or early-stage systems built from scratch.
Benefits
- Medical insurance.
- Vision insurance.
- Dental insurance.
- Must be within commuting distance of HIFI’s Flatiron office and able to work in person most days of the week.
Tech Stack
Solidity
Categories
About HIFI
HIFI builds financial infrastructure and APIs for developers and businesses to move and program money across stablecoins and traditional bank rails, and to manage tokenized treasuries. It sells a B2B platform used by fintechs and enterprises to orchestrate global money flows and enable software-driven payments. Founded in 2022 and headquartered in New York, HIFI operates entities in the U.S., Middle East, and Japan, and facilitates billions in transactions.