Responsibilities

• Develop and maintain Node.js-based backend API servers (NestJS / Express)
• Integrate with blockchain nodes using Web3.js, ethers.js, and JSON-RPC
• Develop cryptocurrency wallet services, deposit/withdrawal logic, and transaction monitoring systems
• Implement backend logic related to DeFi protocols or DEX integrations (preferred)
• Develop large-scale backend systems for multi-chain environments (Ethereum, Polygon, Solana, etc.)
• Operate high-availability services on AWS or GCP cloud infrastructure
• Participate in security issue handling and code reviews

Technical Requirements

Backend / Web Development:

• PHP (5.6 / 7.4)
• MySQL
• Node.js
• CodeIgniter 3
• RESTful API development
• AWS (Amazon Web Services)

Mobile Development (any of the following):

• iOS: Swift, SwiftUI
• Android: Kotlin, Jetpack Compose
• Cross-platform: React Native

Qualifications

• At least 3 years of practical experience with Node.js and TypeScript
• Hands-on experience with either RESTful API or GraphQL
• Experience designing and writing queries for RDBMS (PostgreSQL/MySQL) and NoSQL (Redis/MongoDB)
• Experience collaborating with Git-based workflows is required

Preferred Qualifications

• Experience in fintech, payments, or remittance systems
• Exposure to blockchain-based systems or integrations
• Strong knowledge of security best practices for financial platforms
• Experience with cloud infrastructure (AWS)
• Familiarity with Agile/Scrum methodologies