Design, develop, and deploy secure smart contracts and blockchain protocol integrations across multiple chains. Collaborate with backend and product teams, research DeFi technologies, participate in security audits, and troubleshoot on-chain incidents. The role focuses on scalable Web3 payments infrastructure, cross-chain communication, protocol reliability, and secure smart contract systems.
Capital markets are undergoing a fundamental shift. Assets that live in fragmented systems and manual workflows are moving onto blockchains -systems designed to move and store value more transparently and efficiently.
While this unlocks more open and programmable financial systems, it also introduces significant complexity. For most users, interacting with this new infrastructure is still too difficult.
Fun builds the infrastructure that powers consumer-facing fintech applications - handling onboarding, account access, and money movement so users can interact with blockchain-based systems as seamlessly as they do with traditional finance.
For fintech builders, Fun provides a best-in-class onboarding and deposit stack that drives conversion and unlocks user growth. We operate at the intersection of financial infrastructure, complex engineering, and product experience.
While this unlocks more open and programmable financial systems, it also introduces significant complexity. For most users, interacting with this new infrastructure is still too difficult.
Fun builds the infrastructure that powers consumer-facing fintech applications - handling onboarding, account access, and money movement so users can interact with blockchain-based systems as seamlessly as they do with traditional finance.
For fintech builders, Fun provides a best-in-class onboarding and deposit stack that drives conversion and unlocks user growth. We operate at the intersection of financial infrastructure, complex engineering, and product experience.
Role Overview
We're looking for a Protocol Engineer to join our core blockchain team and help build the foundation of Web3 payments infrastructure. This high-impact role offers the opportunity to work on challenging technical problems at the intersection of smart contracts, cross-chain protocols, and decentralized finance.
You will design and implement secure, efficient smart contract systems and blockchain integrations that power millions of transactions across multiple chains. This role is perfect for a technically strong engineer who thrives in fast-paced environments and wants to shape the future of decentralized finance.
Responsibilities
- Design, develop, and deploy secure smart contracts and protocol implementations across multiple blockchain platforms
- Collaborate with backend and product teams to architect blockchain solutions that meet business requirements
- Write highly efficient, well-tested code and participate in security audits to ensure protocol safety
- Research and evaluate new blockchain technologies, protocols, and DeFi primitives for integration opportunities
- Contribute to incident response and debugging on-chain issues to ensure protocol reliability
Requirements
- Strong experience building and deploying production smart contracts on major blockchain platforms
- Deep understanding of blockchain architecture, consensus mechanisms, and cryptographic principles
- Hands-on experience with smart contract development languages (Solidity, Rust, Move, etc.)
- Solid grasp of DeFi protocols, token standards, and cross-chain communication patterns
- Strong security mindset with knowledge of common smart contract vulnerabilities and best practices
- Clear communicator who can explain complex blockchain concepts to cross-functional teams
Nice to Have
- Production experience with multiple blockchain ecosystems (Ethereum, Solana, L2s, etc.)
- Previously worked at crypto startup or Web3 infrastructure company
- Experience with cross-chain bridges, oracles, or interoperability protocols
- Background with high-volume DeFi protocols or DEX infrastructure
- Contributions to blockchain open source projects or protocol research
- Experience with formal verification or advanced smart contract testing frameworks
Similar Jobs
Artificial Intelligence • Fintech • Insurance • Marketing Tech • Software • Analytics
Investigates and processes moderately complex to complex workers compensation claims, determining coverage, liability, compensability, reserves, damages, and settlements. The role coordinates litigation, engages experts, conducts negotiations and field investigations, and supports arbitrations and mediations. It also provides technical guidance, mentors team members, assists with caseload management, and participates in quality reviews. Candidates need advanced claims-handling and insurance coverage knowledge, strong negotiation and investigation skills, applicable licenses, and typically a bachelor’s degree with 3–5 years of related experience.
Consumer Web • eCommerce • Information Technology • Retail • Software • Analytics • App development
Provides fast, friendly checkout service; operates registers and self-checkout areas; scans and bags merchandise; processes payments and exchanges; answers customer questions; maintains a clean, safe workstation; and assists with stocking, carts, and other store duties as needed.
Top Skills:
Cash RegisterComputerSelf-Checkout Systems
Consumer Web • eCommerce • Information Technology • Retail • Software • Analytics • App development
Receive and unload freight, stock and organize merchandise, prepare delivery orders, and maintain clean, safe backroom and sales-floor areas. Operate forklifts, pallet jacks, scanners, Zebra phones, balers, and other store equipment. Assist customers, verify deliveries, stage and load orders, and support store operations. The role is physically active, requires safe handling of hazardous materials and lifting up to 75 pounds, and may include evening or overnight shifts.
Top Skills:
BalersForkliftsOrders AppPallet JacksScannersZebra Phones
What you need to know about the San Francisco Tech Scene
San Francisco and the surrounding Bay Area attracts more startup funding than any other region in the world. Home to Stanford University and UC Berkeley, leading VC firms and several of the world’s most valuable companies, the Bay Area is the place to go for anyone looking to make it big in the tech industry. That said, San Francisco has a lot to offer beyond technology thanks to a thriving art and music scene, excellent food and a short drive to several of the country’s most beautiful recreational areas.
Key Facts About San Francisco Tech
- Number of Tech Workers: 365,500; 13.9% of overall workforce (2024 CompTIA survey)
- Major Tech Employers: Google, Apple, Salesforce, Meta
- Key Industries: Artificial intelligence, cloud computing, fintech, consumer technology, software
- Funding Landscape: $50.5 billion in venture capital funding in 2024 (Pitchbook)
- Notable Investors: Sequoia Capital, Andreessen Horowitz, Bessemer Venture Partners, Greylock Partners, Khosla Ventures, Kleiner Perkins
- Research Centers and Universities: Stanford University; University of California, Berkeley; University of San Francisco; Santa Clara University; Ames Research Center; Center for AI Safety; California Institute for Regenerative Medicine
