I am looking for an experienced Solidity and Web3 developer to review, debug, and fix issues in an existing smart contract, and ensure it is correctly integrated with a web-based frontend. Scope of Work Review and audit existing Solidity smart contracts for logic, security, and gas-efficiency issues. Identify and fix bugs related to: Incorrect business logic or edge cases. Failing transactions, reverts, or unexpected behavior. Events, access control (roles/ownership), and upgradeability (if any). Ensure compatibility with the target EVM chain (e.g., Ethereum mainnet/testnet, or another EVM-compatible chain) and current Solidity compiler version. Improve or add unit tests where needed to validate the bug fixes. Integrate the fixed contract(s) with the existing Web3 frontend (React/Next.js or similar) using libraries such as ethers.js or web3.js. Fix any issues related to: Reading on-chain data and updating UI state. Writing transactions (Metamask / other wallets), handling confirmations and errors. Network configuration (RPC endpoints, chain IDs), contract addresses, and ABIs. Deliverables Updated Solidity contract(s) with all identified bugs fixed. Updated deployment/migration scripts (Hardhat/Foundry/Truffle, etc.). Updated frontend integration code (Web3 calls, hooks, or services). Brief report summarizing: What bugs were found. How they were fixed. How to deploy and test the updated version. Requirements Proven experience with Solidity and smart contract development. Solid understanding of common Web3 security issues (reentrancy, access control, integer overflows, etc.). Experience integrating contracts with frontend using ethers.js or web3.js. Familiarity with Hardhat, Foundry, or Truffle for compilation, testing, and deployment. Ability to work with Git and existing codebase. Nice to Have Experience with contract audits or using tools like Slither, MythX, or Echidna. Experience with frontend frameworks (React/Next.js) and TypeScript. How to Apply Please include in your proposal: A short description of similar Solidity bug-fixing or Web3 integration work you have done. Links to relevant GitHub repositories or deployed projects. Your estimated timeline and rough budget range for this type of task.