Senior Blockchain Developer – Payment Gateway Platform

As a Senior Blockchain Developer at Dezzex, you will design, build, and scale an enterprise-grade crypto payment gateway platform. You will architect systems that allow businesses and merchants to accept, receive, and manage multi-currency crypto payments, primarily stablecoins like USDC and USDT, alongside traditional fiat bank account payouts. You will lead the integration of Fireblocks API for institutional-grade wallet custody and transaction orchestration, connect automated bank settlement rails, and build reliable multi-chain payment flows.

What you'll do

• Design and develop scalable backend microservices for crypto payment processing, merchant checkout widgets, invoice generation, and transaction reconciliation
• Implement Fireblocks REST APIs, Webhooks, and SDKs for multi-asset vault management, wallet generation, transaction signing, sweep and treasury operations, and policy engine enforcement
• Build native support for USDC and USDT payments across multiple networks (Ethereum, Solana, Polygon, Arbitrum, Base, Tron), managing HD wallet generation, deposit address routing, and gas optimization and fee delegation
• Connect with banking APIs, instant payment networks (such as UAE Aani, India UPI, or global SWIFT and ACH), and liquidity providers for automated crypto-to-fiat conversion and merchant payouts
• Implement real-time FX-rate lookup and dynamic pricing engines to accept payments in various cryptocurrencies while settling to merchants in their preferred local fiat or stablecoin currency
• Build real-time blockchain event indexers, transaction monitoring systems, and webhook engines capable of handling re-orgs, gas spikes, and partial payment edge cases
• Enforce robust security practices around key management, transaction signing, AML and KYT screening (Chainalysis, Elliptic), and Travel Rule compliance for cross-border flows

What you bring

• 3-6+ years of professional software development experience, with 2+ years dedicated to production-grade Web3 and blockchain solutions
• Hands-on experience integrating Fireblocks API and SDK (vault creation, transaction creation, webhooks, asset management)
• Deep understanding of payment gateway architecture including payment intents, webhook handling, reconciliation engines, double-entry ledgers, and transaction finality tracking
• Proven experience building native USDC and USDT transaction flows (ERC-20, SPL, TRC-20 token standards)
• Proficiency in Node.js and TypeScript, Go (Golang), or Python for high-throughput backend services
• Experience integrating with banking APIs and payment processors (open banking, SWIFT, ACH, local real-time rails)
• Solid understanding of EVM smart contracts (Solidity and Vyper) and interacting with blockchain RPC nodes via Web3.js, Ethers.js, or Viem

Nice to have

• Prior experience at a crypto payment service provider (PSP), FinTech, or Web3 payment gateway
• Experience with cross-chain swaps, DEX aggregators, or liquidity providers (1inch, Uniswap, Circle Cross-Chain Transfer Protocol)
• Familiarity with GCC financial regulations (VARA, CBUAE) or RBI digital asset directives
• Knowledge of containerized infrastructure (Docker, Kubernetes, AWS, GCP, Redis, PostgreSQL)

What we offer

• Competitive salary package with performance bonuses and token and equity incentives
• Opportunity to build a core product at the intersection of Web3 and global fintech
• Relocation assistance for Dubai or remote flexibility
• Collaborative engineering culture focused on ownership, security, and high performance

Location

Based in or willing to relocate to Dubai, UAE or India. Flexible working arrangements available.