Software Engineer - Blockchain

As a Software Engineer specializing in Blockchain at Flexsin, you develop and deploy smart contracts across Solana and EVM-compatible chains, and build full-stack decentralized applications with secure wallet integrations and cross-chain functionality.

What you'll do

• Develop and deploy smart contracts on Solana using Rust and Anchor, and on EVM-based networks using Solidity
• Build full-stack dApps with React.js/Next.js, Web3.js/Ethers.js, and wallet integrations such as MetaMask, Phantom, and WalletConnect
• Implement cross-chain features using LayerZero, Wormhole, or Axelar for bridging, syncing, and wrapped tokens
• Write secure, gas-optimized contracts and perform thorough testing with Mocha, Jest, Anchor test suite, Hardhat, and Foundry
• Integrate backend services with Node.js, GraphQL/REST APIs, PostgreSQL/MongoDB, and Redis
• Automate deployments using Docker and CI tools such as GitHub Actions and GitLab CI
• Monitor and troubleshoot on-chain activity using Tenderly, Etherscan APIs, and Solana Explorer
• Collaborate with frontend and DevOps teams to ensure great user experience and scalable infrastructure

What you bring

• 3+ years of full-stack development experience
• 1+ year of hands-on Solana smart contract development with Rust and Anchor
• Proficiency in Solidity and EVM tools such as Hardhat, Foundry, and Truffle
• Strong knowledge of Web3 wallet integration, blockchain architecture, and RPC interactions
• Experience with DeFi, NFTs, DAOs, and decentralized storage such as IPFS and Arweave
• Familiarity with authentication protocols like JWT, OAuth2, and SIWE (Sign-In With Ethereum/Solana)
• Understanding of smart contract vulnerabilities and Web3 security best practices

Nice to have

• Experience with zk-rollups such as zk-SNARKs, zkSync, and StarkNet
• Exposure to other chains like Cosmos or NEAR, or React Native/mobile dApps
• Contributions to open-source blockchain projects
• Knowledge of MEV, gas fee estimation, and bridging mechanics across chains