LinkedIn: https://www.linkedin.com/in/maciejlozinski/ e-mail: loziniak@o2.pl

Video demo: https://share.robotix-lozinski.pl/index.php/s/LRzPgreYWaqp59z

1. Smart Contract: Voting.sol

   • addCandidate(string name) – Only owner
   • vote(uint candidateIndex) – One vote per user
   • getCandidates() – Returns all candidates & vote counts
   • getWinner() – Returns winner’s name

2. Backend (Node.js + Web3.js)

(not implemented, use Node.js scripts to interact with contract, see below)

3. Rules
   • Prevent double voting from the same address.
   • Only allow valid proposal IDs.
   • Use simple mappings and structs — no external libraries required.

Notes:

• Saving strings to blockchain is not optimal to me, I'd suggest using database instead.
• I'd also suggest interacting with smart contract from frontend, with use of a wallet like MetaMask, instead of backend REST endpoint.

Prepare:

cd onchain
npm install

Test:

Smart contract tests are located in onchain/test/Voting.ts file.

npx hardhat test

Run test blockchain node:

npx hardhat node --network hardhatMainnet

Deploy smart contract:

npx hardhat run scripts/voting-deploy.ts --network localhost

This will print contract address to use later when interacting with contract...

Interact with contract:

Example interactions with the contract are performed by Node.js scripts, through "ethers" library. With little modification (use BrowserProvider instead of JsonRpcProvider, see comments in scripts) this could be executed from frontend with using MetaMask.

<contract-address> example: "0xcf7ed3acca5a467e9e704c703e8d87f634fb0fc9"

node scripts/voting-add-candidate.ts "First Candidate" <contract-address>
node scripts/voting-add-candidate.ts "Second Candidate" <contract-address>
node scripts/voting-vote.ts 0 <contract-address>

• Cryptocurrency-enabled property transactions
• Mobile-responsive design
• SEO-optimized architecture
• Real-time market data integration
• Interactive 3D property visualization
• Smart contract integration for secure transactions

The platform is built using:

• React for component-based architecture
• Tailwind CSS for responsive styling
• React Router for client-side routing
• Three.js for 3D property visualizations
• Web3.js for blockchain interactions

Special thanks to the Arrived.com team for inspiration and the React/Tailwind CSS communities for their continued support and resources.