BACKEND/BLOCKCHAIN ENGINEER

Wanoyu Global; Kuala Lumpur; On-site; MYR 120,000 - 180,000; Full time

Benefits offered by this job

Job summary

COINYEX is seeking a Backend / Blockchain Engineer to build and maintain the TUX WALLET backend, APIs, and cross-chain integrations. You will work on secure, scalable financial infrastructure and contribute to Web3-based services in a Linux/Git environment.

You will collaborate on REST and WebSocket services, ERC-20 token integration, and cross-chain protocols while ensuring reliability and secure operation in production.

Qualifications

• Proficient backend development experience.
• Experience designing and developing APIs.
• Practical blockchain/Web3 knowledge.
• Comfortable with Linux and Git/GitHub.
• Able to communicate technical matters in English.
• Independent researcher and learner of new technologies.
• Focus on security, scalability, reliability and failure scenarios.

Responsibilities

• Design, develop, and maintain backend and blockchain-related systems.
• Build and maintain the TUX WALLET backend.
• Design and develop REST APIs and WebSocket services.
• Work with databases, caching, queues, and asynchronous processing.
• Integrate Ethereum and other EVM-compatible blockchains.
• Handle RPC providers, gas, nonces, and confirmations.
• Integrate ERC-20 tokens and smart contracts.
• Monitor on-chain data and blockchain events.
• Contribute to DEX/Swap integrations.
• Work with cross-chain and omnichain technologies.
• Integrate external APIs including payment, KYC, on/off-ramp, exchange, banking, and card services.
• Build secure, scalable, and highly reliable financial infrastructure.
• Implement monitoring, logging, authentication, authorization, and security controls.

Skills

Backend development

API design

English communication

Independently learn new tech

Security mindset

Tools

Node.js/TypeScript

Python

NestJS

Redis

REST/WebSocket APIs

PHP

Job description

COINYEX is building the next generation of financial technology centered around TUX WALLET, a Web3 wallet ecosystem combining digital assets, blockchain, Web3, payment services, AI, and other emerging technologies.

We are looking for a Backend / Blockchain Engineer who can work beyond conventional backend development and contribute to real-world blockchain and Web3 infrastructure.

This is an opportunity to become a core technical contributor to the long-term development of our platform.

We are looking for someone who:

• Has professional backend development experience
• Has experience designing and developing APIs
• Has practical blockchain / Web3 knowledge
• Can work confidently in Linux and Git/GitHub environments
• Can communicate technical matters in English
• Is comfortable researching and learning new technologies independently
• Thinks about security, scalability, reliability, and failure scenarios, not just functionality

What You’ll Do

You will be involved in designing, developing, and maintaining backend and blockchain-related systems, including:

• Build and maintain the TUX WALLET backend
• Design and develop REST APIs and WebSocket services
• Work with databases, caching, queues, and asynchronous processing
• Integrate Ethereum and other EVM-compatible blockchains
• Work with RPC providers, blockchain transactions, gas, nonces, and confirmations
• Integrate ERC-20 tokens and smart contracts
• Process and monitor on-chain data and blockchain events
• Contribute to DEX / Swap integrations
• Work with cross-chain and omnichain technologies
• Integrate external APIs including payment, KYC, on/off-ramp, exchange, banking, and card services
• Build secure, scalable, and highly reliable financial infrastructure
• Implement monitoring, logging, authentication, authorization, and security controls

Experience with some of the following technologies is highly valued:

• Node.js / TypeScript
• Python
• NestJS
• Redis
• REST / WebSocket APIs
• PHP

Blockchain / Web3

• Ethereum / EVM
• Solidity
• Ethers.js / Web3.js / Viem
• Smart Contract Integration
• ERC-20
• RPC / On-chain Data
• Transaction Monitoring
• Blockchain Indexing

DEX / Swap

• Uniswap
• 1inch
• KyberSwap
• LI.FI
• 0x
• ParaSwap
• GMX
• ChangeNOW
• Chainlink CCIP
• Wormhole
• Bridges / Cross-chain Messaging
• Omnichain Architecture

Infrastructure

• AWS
• Docker
• CI/CD / GitHub Actions
• Monitoring / Observability

Security Matters

• API security
• JWT / OAuth
• Encryption
• Secrets management
• Access control
• Audit logs
• Private key security concepts
• Multisig
• Smart contract risks
• Transaction and signature verification

AI experience is not mandatory, but candidates with experience in the following will have an advantage:

• LLMs
• AI Agents
• MCP
• Function / Tool Calling
• RAG
• Vector Databases
• Agent Orchestration
• Multi-Agent Systems

We are particularly interested in engineers who understand how AI agents can safely interact with APIs and blockchain functions through appropriate permissions and execution controls.