Protocol Engineer

**Fun.xyz** Protocol Engineer; $120–300k across L1–L4 + equity; Midtown NYC HQ preferred (Singapore considered)

**About the Role** Protocol Engineers own smart contract design, deployment, and security across the blockchain platforms that power Fun's Checkout payments infrastructure. You'll work closely with the backend and product engineering teams to translate payment, routing, and settlement requirements into secure, production-grade on-chain systems, partnering directly with the team's existing Solidity engineers and protocol lead.

**Responsibilities** - Design and deploy secure smart contracts across the blockchain platforms Fun's payment infrastructure touches. - Partner with backend and product engineering on end-to-end architecture for payments, routing, and settlement flows spanning on-chain and off-chain systems. - Write efficient, well-tested contract code and participate in internal and third-party security audits. - Research new blockchain technologies and DeFi primitives to inform the protocol roadmap. - Own incident response and remediation for on-chain issues.

**Required Skills** A. Production smart contract development experience on major blockchains. B. Proficiency in Solidity; Rust or Move a plus. C. Deep understanding of blockchain architecture, consensus mechanisms, and cryptographic principles. D. Strong security mindset — can reason about smart contract vulnerabilities and attack surfaces.

**Bonus Skills** - Multi-ecosystem blockchain experience. - Prior crypto startup or Web3 infrastructure background. - Cross-chain bridge or oracle protocol experience. - High-volume DeFi/DEX infrastructure experience. - Open source blockchain contributions.

**Logistical Info** - Location: Midtown NYC HQ preferred; in-person Mon–Thu, optional remote Friday. Singapore considered only in exceptional cases with visa support. - Compensation: $120–300k across L1–L4, with equity scaled by level. - **Other:** H-1B transfers and US domestic relocation supported for US candidates; international relocation and new visas generally not supported.

**Ideal Background** - Protocol/smart contract engineers from crypto-native companies or top Web3 infra teams. - Client wants senior/staff-level protocol engineers — they passed a more junior profile as too junior for current team needs (10/6). - Comparable bar to the Singapore Protocol Engineer req — same seniority/skill bar per the Sept 22 client call (recruiter-only inference — that note was recorded against the Singapore req, not confirmed against this NYC one directly).

**Green Flags** - Shipped smart contracts in production handling real value, not just testnet/hackathon work. - Comfortable working cross-functionally with backend and product engineering.

**Red Flags** - No production (mainnet) smart contract experience. - Narrow blockchain-specialist background with no broader distributed-systems context.

**Interview Process** 1. Recruiter screen with Caroline to confirm technical depth, location, and compensation expectations. 2. Hiring manager technical screen with existing Solidity engineer and/or protocol lead (deep dive on past work). 3. Technical assessments on smart contract design, code review, and security thinking (live and/or take-home). 4. Onsite in NYC for broader technical and culture interviews; potential founder/CTO session.