Senior Full Stack Engineer (Checkout)

Skills

About the Role

You will own the Checkout backend and frontend, building and maintaining the end to end flows that power funding, provider integrations, and recovery in a fast growing Web3 checkout product. You’ll design robust backend contracts with provider systems and Checkout UI, work across Core backend and Partner Portal as needed, and contribute frontend work when UI states and contracts need alignment. You’ll collaborate with multiple teams, communicate clearly, and adapt as priorities evolve while delivering reliable, scalable features for users.

Requirements

• Strong backend engineering experience with expert proficiency in TypeScript Node.js plus full stack ability to work across API contracts and UI states using React and TypeScript Viem and Wagmi a plus
• Proven experience integrating external APIs with provider specific edge cases with good instincts around async flows failures observability and recovery
• Web3 knowledge including transactions block explorers and how products like bridges and DEX aggregators fit together
• Strong product judgement and ability to navigate multiple teams and codebases without hand holding
• Excellent communication skills in English and comfort in a fast paced environment where priorities evolve quickly

Responsibilities

• Own Checkout specific backend capabilities that power funding flows end to end including provider integrations quotes sessions statuses deposit addresses and recovery
• Design and build integration patterns for external providers onramp exchange and payment normalising provider specific behaviour into a consistent Checkout experience
• Define and maintain the backend contracts between Checkout UI provider systems and LI.FI's execution infrastructure including robust state handling across long running and failure prone flows
• Drive cross functional technical discovery when Checkout depends on Core backend Partner Portal or other adjacent teams ensuring architectural alignment without drift
• Implement frontend work where useful particularly when UI states and backend contracts need to be designed together

Benefits

• Annual team offsites
• 30 days of PTO
• Flexible remote days
• Flexible working hours
• Equity participation from day 1
• Equipment provided
• Personal development budget €1,000 after 6 months
• Remote budget €1,000