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©2026 EDITION
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Building from First Principles

Architecting
On-Chain Systems.

I am Harsh. I focus on learning smart contract development by building financial logic and decentralized systems from scratch.

Explore Projects GitHub
[ 01 ]

Portfolio Overview

I build smart contracts from scratch - no frameworks, no shortcuts. Over the past months I've written and deployed 21 production-level Solidity contracts covering ERC20, ERC721, AMMs, lending protocols, flash loans, proxy patterns, and DeFi primitives. Every contract built from first principles.

My focus is on contract architecture, security patterns, and how decentralized systems actually work in production. I understand reentrancy, CEI patterns, storage slot collisions, gas optimization, and the full ERC standard ecosystem. I want to contribute to serious DeFi infrastructure and protocol engineering.

[ 02 ]

Project Index

TOKENOMICS // VESTING

Token Vesting Contract

Production-ready ERC20 token vesting system with per-beneficiary cliff periods and linear unlock. Built from scratch with NatSpec documentation, events on every action, and deployed on Ethereum Sepolia.

Solidity ERC20 Linear Vesting Cliff Logic
View Repository → View on Etherscan →
Sepolia Testnet Deploy
Linear Cliff + Unlock
vested = totalAmount * elapsed / vestingDuration;
NFT // DUTCH AUCTION

NFT Dutch Auction

Single contract combining ERC721 NFT minting with a declining price auction. First buyer gets the NFT minted directly to their wallet. Excess ETH auto-refunded. Deployed on Sepolia.

Solidity ERC721 Dutch Auction
View Repository → View on Etherscan →
RANDOMNESS // LOTTERY

Decentralized Lottery

Trustless lottery using commit-reveal scheme for fair randomness - no oracles needed. Players commit a hash, reveal their number, highest wins 90% of the pot. Auto-reset between rounds. Deployed on Sepolia.

Solidity Commit-Reveal Trustless
View Repository → View on Etherscan →
IDENTITY // STATE MANAGEMENT

OnChain Reputation System

A smart contract system where users can register and earn reputation points on-chain. The contract tracks activity and assigns reputation tiers based on accumulated points. Built to deeply understand user state management, mappings, structs, and frontend integration.

Solidity Mappings & Structs Frontend Integration
View Repository →
On-Chain Data Storage
Tiered Reputation Logic
struct User {
  uint256 reputation;
  bool isRegistered;
}
mapping(address => User) public users;
DEAL LIFECYCLE // FINANCE

Escrow Contract

A decentralized escrow allowing two parties to securely transact. Funds are locked until both sides complete the deal flow. Taught me financial state machines and secure ETH transfers.

Solidity Access Control
View Repository →
TOKENOMICS // STANDARDS

ERC20 Implementation

A custom implementation of the ERC20 standard built from scratch. Includes transfer, approvals, allowance tracking, minting, and burning mechanics.

Solidity Token Mechanics
View Repository →
YIELD // TIME-LOCKS

Advanced Vault

A time-locked vault contract where users can deposit ETH and withdraw only after a specific lock period. Focuses intensely on time-based restrictions, safe withdrawal patterns, and contract balance management.

Solidity Time-Locks Accounting
View Repository →
FULL-STACK // WEB2

Job Portal

A comprehensive platform bridging frontend and backend systems. Engineered to master full-stack integration and database architecture.

React.js Python MySQL
POOL LOGIC // REWARDS

ETH Staking Contract

A complex staking contract where users deposit ETH and earn rewards over time. The system meticulously tracks user stake, reward accumulation, and allows users to claim rewards or unstake.

Solidity Reward Math Pool Architecture
View Repository →
[ 03 ]

Technical Stack

I am building a comprehensive foundation in the Ethereum ecosystem, focusing on smart contract development, seamless frontend integration, and essential developer tooling.

Smart Contract Patterns

  • ERC20 / ERC721 Standards
  • Proxy & Upgrade Pattern
  • Flash Loans / AMM / Lending
  • Token Vesting & Lockups
  • Commit-Reveal Scheme
  • Dutch Auction Mechanism

Security & Optimization

  • Reentrancy Guards / CEI Pattern
  • Pull Over Push Pattern
  • Storage Slot Packing
  • Gas Optimization
  • Access Control / Role-Based Auth
  • State Machine Design

Tooling & Stack

  • Solidity 0.8+
  • Remix / Hardhat
  • Ethers.js / Web3.js
  • React.js & JavaScript
  • Git & GitHub
  • Base / Ethereum / Sepolia
SOLIDITY // YUL // DEFI // SMART CONTRACTS // ZERO KNOWLEDGE // OP SEC // EVM // WEB3 // PROTOCOL ENGINEERING // SOLIDITY // YUL // DEFI // SMART CONTRACTS // ZERO KNOWLEDGE // OP SEC // EVM // WEB3 // PROTOCOL ENGINEERING //
[ 04 ]

Operational Trajectory

2025 - PRESENT // SMART CONTRACT DEVELOPMENT

Solo Protocol Engineer

Built 21 production-level Solidity contracts from scratch covering ERC20, ERC721, AMMs, lending protocols, flash loans, proxy patterns, and DeFi primitives. Deployed three portfolio projects on Ethereum Sepolia.

PRE-2021 // CYBERSECURITY

White Hat Bug Hunter

Operated as an independent security researcher before transitioning fully into Web3. Hunted vulnerabilities and audited system architectures across numerous Web2 FinTech applications, building a foundational mindset for zero-trust engineering.

JAN 2025 - APR 2025 // DIPC SOFTWARE

Full-Stack Engineering Intern

Engineered full-stack applications and integrated complex systems using React.js. Focused on bridging robust frontend interfaces with secure, scalable backend architectures.

2021 - 2025 // GUJARAT TECHNOLOGICAL UNIVERSITY

B.E. Information Technology

SAL Engineering and Technical Institute. Maintained an 8.05 CGPA while aggressively pivoting theoretical computer science fundamentals into practical Web3 and cryptography applications. Currently building toward smart contract security auditing and contributing to open-source DeFi protocols.

[ 05 ]

What I Can Build

If you are building a Web3 product and need a smart contract developer - here is exactly what I can ship for you.

DeFi Protocols

  • AMM / DEX contracts
  • Lending & borrowing systems
  • Staking & reward pools
  • Flash loan receivers
  • Yield strategies

Token Systems

  • ERC20 tokens from scratch
  • Token vesting & lockups
  • ERC721 NFT contracts
  • Dutch & English auctions
  • Governance contracts

Infrastructure

  • Upgradeable proxy contracts
  • Multi-sig wallets
  • Access control systems
  • Escrow & deal flows
  • Lottery & randomness
[ 06 ]

The Frontier

I’m currently pushing my boundaries by focusing on smart contract security and professional development workflows used in real-world blockchain projects.

Areas of Active Exploration

  • Hardhat + Foundry  for advanced testing, forking, and deployment workflows
  • Smart contract auditing - formal verification and professional audit reports
  • Slither + Echidna  for static analysis and fuzz testing
  • Chainlink  oracles - price feeds, VRF, and automation
  • Layer 2 architecture  - Base, Optimism, Arbitrum deployment patterns
  • ZK proofs  - zero knowledge fundamentals and circuit design
  • MEV  - flashbots, transaction ordering, and sandwich attack prevention

Ready to
Contribute.

My goal is to become a reliable smart contract developer who can design secure and efficient on-chain systems for serious blockchain infrastructure.

Open Transmission