Senior Blockchain Engineer

As a Senior Blockchain Engineer at MoonPay, you design and operate high-volume transaction infrastructure that moves value across blockchains at scale. You own transaction lifecycle management, wallet infrastructure, and cross-chain integrations that power 30M+ customers and 500+ ecosystem partners. You'll work on hard problems where outcomes matter more than process, and where your ownership directly impacts the operating system for value movement.

What you'll do

• Design and improve high-volume transaction broadcasting pipelines, managing transaction lifecycle from broadcast through detection, retry, rebroadcast, and safe recovery of stuck transactions
• Contribute to wallet infrastructure and automation systems, implementing safe parallel transaction handling and improving monitoring, observability, and operational guardrails
• Design systems with financial correctness, reconciliation, and auditability in mind
• Build infrastructure supporting cross-chain and multi-step flows, handling non-atomic journeys across chains and designing state machines and recovery strategies for partial failure scenarios
• Support routing mechanics and swap execution considerations including price impact, liquidity changes, and MEV awareness
• Build reliable off-chain services that interact with on-chain contracts
• Participate in estimation, planning, and execution of projects, features, and integrations
• Develop and maintain thoroughly tested, high-quality, and performant code
• Collaborate closely with Product Managers to design scalable implementation strategies
• Contribute to reliable, maintainable systems that evolve with product needs
• Participate in incident response and post-mortems, and improve reliability, alerting, and system resilience
• Continuously evolve infrastructure to support growing volume and complexity

What you bring

• Strong backend and platform engineering fundamentals
• Experience operating production systems with real uptime requirements
• Hands-on experience interacting with live blockchain networks in production
• A clear understanding of transaction lifecycle in at least one blockchain and failure recovery patterns
• You think in failure modes, not just happy paths

Nice to have

• You can explain a real production incident end-to-end
• Experience with at least one wallet infrastructure such as Ethereum, Bitcoin, or Solana, or custody systems
• Awareness of MEV, slippages, pricing impact, and swap execution risks
• Experience with high-throughput or financial systems
• Experience working at exchanges, custody providers, wallet infrastructure teams, or high-volume DeFi platforms
• Familiarity with UTXO-based chains such as Bitcoin, including coin selection and fee bumping strategies such as RBF and CPFP
• Experience designing cross-chain or multi-step transaction orchestration systems
• Familiarity with blockchain indexing or event ingestion pipelines
• Understanding of common token standards such as ERC-20 and SPL, and interacting with smart contracts from backend services

What we offer

• Salary of $150,000 to $210,000
• Equity package with ownership for all employees
• Pay-for-performance equity bonus for those driving outsized outcomes
• Moonshot award of $250,000 in equity for 20 employees per year with exceptional impact
• Employer pension contributions from day one
• Employee referral program earning $10,000 in USDC
• Flexible time off and end-of-year recharge period for company-wide rest
• Birthday leave and enhanced parental leave
• Hybrid working schedule, fully remote or from your nearest Moonbase
• Commuter benefits for public transport
• Private healthcare benefits
• Wellhub wellness membership
• Enterprise access to Claude, ChatGPT, Gemini, and the latest AI tools
• Lunch credit on office days and home office setup allowance
• Remote working allowance for those working fully remotely
• Monthly product budget and zero-fee crypto transactions
• $1,000 annual training budget and High Potential Program with structured development and mentorship
• Regular remote company offsites with high-impact in-person sessions and hackathons
• Cycle to Work scheme (Ireland) and EV Salary Sacrifice (UK)

About MoonPay

MoonPay is a high-standards, high-velocity company building the operating system for value movement. Through four offerings-fund, tokenize, trade, and spend-MoonPay serves 30M+ customers and 500+ ecosystem partners, moving crypto, stablecoins, and tokenized assets. Licensed in the U.S. and regulated across the UK, EU, Canada, and Australia, MoonPay was recognized as Forbes' America's Best Startup Employers 2026, ranked 2nd in Crypto Services on Fortune's inaugural Crypto 100, and won The Sunday Times Best Places to Work two years running.