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Senior Smart Contract Developer - Pet360 (Blockchain, Solidity, EVM)

$70 - $120 per hour
Full-time

About the Project

We are building Pet360 — the first blockchain-based pet ecosystem in Brazil. 160 million pets, $60 billion market, zero blockchain infrastructure today.

Our Web2 platform is 75% complete. We are now building the Web3 layer from scratch — pet NFT passports, vaccine certificates, smart contract adoptions, and on-chain pet insurance.

We are looking for a Senior Smart Contract Developer to join our team.

What You Will Do

  • Write and deploy Solidity smart contracts (ERC-721 for pet passports, ERC-1155 for vaccine certificates)
  • Implement upgradeable contract patterns (UUPS) for future flexibility
  • Write comprehensive tests using Foundry or Hardhat
  • Optimize gas usage and ensure security best practices
  • Design the on-chain architecture for pet identity, vaccine verification, and insurance claims
  • Work alongside our backend and frontend teams

What We Are Looking For

  • 3+ years of software development experience
  • 1+ year of Solidity and EVM development
  • Strong understanding of ERC-721 and ERC-1155 standards
  • Experience with Foundry or Hardhat
  • Understanding of smart contract security and gas optimization
  • Experience with upgradeable contract patterns (UUPS or Transparent proxies)
  • Professional English proficiency

Nice to have:

  • Experience with multi-chain deployments (Polygon, Ethereum, BSC)
  • Experience with smart contract auditing
  • Experience with IPFS and decentralized storage
  • Experience with AI-assisted development (Cursor, Claude Code)

What We Offer

  • Fully remote — work from anywhere
  • Contract with long-term growth potential
  • 30+ hours per week
  • $70-120 per hour (negotiable)
  • Founding team token allocation
  • Payment in crypto (USDC/USDT) or fiat (Wise/PayPal)

Vacancy posted 6 hours ago
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