Sanjay S.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

Hi, I'm Sanjay, a seasoned Blockchain & Backend Engineer with 5+ years of experience specializing in Rust-based smart contracts, Solana programs, and full-stack decentralized application development. I’ve delivered robust systems across the blockchain spectrum — from DeFi protocols and NFTs to MPC wallets and Layer 1 chains — on networks like Solana, Ethereum, Polygon, and Stellar. My expertise is in both smart contract engineering and backend systems, including Rust microservices and NestJS/Node.js apps for real-time crypto platforms. Key Highlights: Built secure Solana smart contracts: token minters, vesting contracts, and referral systems using PDAs (Migrated Solidity smart contracts to Solana Anchor with full feature) Architected MPC Wallet services with Shamir’s Secret Sharing scheme (Rust, microservices) Developed a cross-border crypto payment wallet on Stellar SEP protocols with a NestJS/Node backend Implemented a Kafka-based notification and message dispatcher in Rust to deliver messages over Email, SMS, WebSockets, and polling Created XP reward systems using custom ERC20, ERC1155 (Soulbound), and ERC721 tokens Contributed to major open-source blockchain projects: Solana, Stellar Kelp, Substrate, Polygon Edge 💡 I can help you with: Smart Contract Development (Rust, Solidity, Anchor) Backend Systems in Rust, Node.js/NestJS (microservices, APIs, Kafka, Redis) Cross-chain NFT / Token Systems (Solana, Ethereum, Polygon) MPC Wallets and cryptographic infrastructure Blockchain consulting & architecture 🔗 Notable Contributions: (Links can be found below) Solana Core Hashing Refactor (keccak, blake3, sha256) Solana SPL Token Enhancements Stellar Kelp AMM Enhancements (used by 100k+) Substrate How-To Guide Contributions Polygon Edge Appchain CLI Docs I bring a rare combination of protocol-level blockchain skills and real-world backend development experience. Whether you need a Solana Rust developer, a full-stack DApp engineer, or a technical lead to guide your blockchain product — I'm ready to jump in and help you succeed.