DEX (from learnweb3.io)

Things that I've learned..

Built an exchange with only one asset pair ($ETH<>$CD (Crypto Dev tokens))
The Decentralized Exchange take a fee of 1% on swaps
When users add liquidity, they are given (Crypto Dev LP) tokens
Used Hardhat for smart contract deployment, as well as importing Openzeppelin's ERC20 Contract
Got API keys from Alchemy and Rinkeby Faucet
npm install Web3Modal library in order to connect DeFI dApp to the Metamask wallet
Wrote some code like "addliquidity.js", "removeliquidity.js", "swap.js", etc..

Here's a screenshot of the DeFi DEX that I've built..