Java Backend Engineer – On-Chain Payment Integration

Keystone AI is a leading global blockchain ecosystem behind the world’s largest cryptocurrency exchange by trading volume and registered users. We are trusted by 300+ million people in 100+ countries for our industry-leading security, user fund transparency, trading engine speed, deep liquidity, and an unmatched portfolio of digital-asset products. Keystone AI offerings range from trading and finance to education, research, payments, institutional services, Web3 features, and more. We leverage the power of digital assets and blockchain to build an inclusive financial ecosystem to advance the freedom of money and improve financial access for people around the world. We are looking for a Java Backend Engineer with on-chain development experience to join our On-Chain Payments team. You will build the backend infrastructure that bridges traditional banking rails and blockchain networks, enabling seamless fiat-to-crypto conversion and on-chain transaction processing. Responsibilities Design and develop backend systems for on-chain payment flows, including wallet interactions, transaction broadcasting, and confirmation tracking Integrate with blockchain networks (EVM-compatible chains and others) for on-chain fund settlement Build APIs and services that connect banking channels with on-chain liquidity Collaborate with the P2P and Fiat teams on cross-system integrations Ensure transaction reliability, idempotency, and fault tolerance across on-chain and off-chain systems Monitor chain status and handle edge cases such as reorgs, gas spikes, and failed transactions Requirements 3–5 years of Java backend development experience Experience with Web3/blockchain development: on-chain interactions, wallet integrations, smart contract calls Familiarity with EVM chains (Ethereum, BSC, etc.) or other L1/L2 ecosystems Proficiency in Spring Boot and common distributed system components Fluency in English is required to be able to coordinate with overseas partners and stakeholders. Additional languages would be an advantage. Experience in fintech or crypto payment systems is a strong plus Why Keystone AI • Shape the future with the world’s leading blockchain ecosystem • Collaborate with world-class talent in a user-centric global organization with a flat structure • Tackle unique, fast-paced projects with autonomy in an innovative environment • Thrive in a results-driven workplace with opportunities for career growth and continuous learning • Competitive salary and company benefits • Work-from-home arrangement (the arrangement may vary depending on the work nature of the business team) Keystone AI is committed to being an equal opportunity employer. We believe that having a diverse workforce is fundamental to our success. By submitting a job application, you confirm that you have read and agree to our Candidate Privacy Notice . Originally posted on Himalayas