Yatharth Singh / Solidity Developer
Production-minded Ethereum systems with custom authorization, measurable security constraints, and polished product interfaces—from ERC-4337 accounts to automated payment vaults.
01 / Selected work
Focused portfolio work across payments, account abstraction, authorization and token infrastructure.
A smart-contract payment vault for controlled, automated on-chain payments. Users authorize EIP-712 payment intents while the contract enforces recipient allowlists, nonces, deadlines, per-transaction limits and daily spend rules.
A session-key gaming wallet built around ERC-4337 v0.7. The owner authorizes a tightly scoped session once; the app can then execute only the permitted game action within a fixed USDC budget and expiry window.
A custom 3-of-5 smart account that validates multiple ECDSA signatures inside the ERC-4337 execution path. It rejects duplicate and unauthorized signers, while a whitelist paymaster can sponsor approved UserOperations.
A backend-free launchpad where a factory deploys fixed-supply ERC-20 tokens and isolated presales. Inventory is escrowed on-chain, settlement is permissionless, and contributors receive claims or full refunds based on the final outcome.
02 / More engineering work
Smaller protocol experiments and product builds from my GitHub. The four projects above remain my primary case studies.
Governor, voting token and timelock-based execution flow built and tested with Foundry.
An ERC-4337 learning implementation covering EntryPoint validation and UserOperation execution.
A proof-based ERC-20 claim system using Merkle roots for efficient eligibility verification.
Rebase token, vault and token-pool contracts for cross-chain transfers through Chainlink CCIP.
A collateral-backed stablecoin system with health-factor checks and a connected web interface.
An ERC-721 minting project focused on contract deployment and on-chain asset ownership.
A contract-led escrow workflow with a frontend for funding, settlement and state visibility.
An earlier multisig implementation exploring owner approvals and threshold-based execution.
A Solidity auction contract covering bids, auction state and winner settlement.
A compact on-chain voting application for registering choices and enforcing voting rules.
A price-feed-aware funding contract with minimum contribution and owner withdrawal logic.
A React crypto-market interface for exploring assets and tracking market information.
03 / Expertise
I work across the full Web3 delivery path, while keeping Solidity architecture at the center.
Custom authorization, vaults, factories, token mechanics, governance and DeFi primitives.
Permission boundaries, replay protection, signature validation, unit tests and fuzz testing.
Wallet flows, typed-data signing, contract reads/writes and product-ready frontend states.
Responsive interfaces that turn complex on-chain flows into understandable user journeys.
04 / Experience
Independent / Freelance
Translating product requirements into tested smart contracts and responsive web experiences. My freelance work covers architecture, implementation, wallet integration, interface delivery and deployment-ready handoff for independently built products.
05 / Resume
A concise one-page resume covering my strongest smart-contract projects, freelance experience, education and current Web3 stack.
06 / About
I’m a Computer Science graduate and Solidity developer based in Delhi. My work is centered on secure contract behavior, clear testing, and the product layer that makes on-chain systems usable. I’m most interested in account abstraction, payment infrastructure and protocol security.
07 / Contact
I’m available for smart-contract roles, freelance builds and technical collaborations.