Decentralized Finance (DeFi) Case Studies

Overview

Uniswap is a decentralized exchange that allows users to swap various cryptocurrencies without the need for an order book.

Key Features

• Automated Market Maker (AMM) model
• Liquidity provision by users
• ERC-20 token support

Code Example: Creating a Simple Swap

                // Example of a Uniswap swap function in Solidity
                function swap(uint amountIn, address tokenIn, address tokenOut) external {
                    // Get the Uniswap router
                    IUniswapV2Router02 router = IUniswapV2Router02(uniswapRouter);
                    // Approve token transfer
                    IERC20(tokenIn).approve(address(router), amountIn);
                    address[] memory path = new address[](2);
                    path[0] = tokenIn;
                    path[1] = tokenOut;
                    // Execute swap
                    router.swapExactTokensForTokens(amountIn, 0, path, msg.sender, block.timestamp);
                }
                

Overview

Aave is a decentralized lending platform that allows users to lend and borrow cryptocurrencies.

Key Features

• Flash Loans: Uncollateralized loans that must be paid back within one transaction block.
• Stable and Variable Interest Rates
• Collateralized Borrowing

Steps to Borrow on Aave

1. Deposit collateral into the Aave protocol.
2. Choose the asset to borrow and the interest rate type.
3. Confirm the transaction to borrow funds.

Overview

MakerDAO is a decentralized credit platform on the Ethereum blockchain that facilitates the generation of the DAI stablecoin.

Key Features

• Collateralized Debt Positions (CDPs)
• DAI Stablecoin pegged to USD
• Governance through MKR token holders

Creating a DAI Loan

                // Example of creating a CDP in Solidity
                function createCDP(uint collateralAmount) external {
                    // Approve collateral transfer
                    IERC20(collateralToken).approve(address(makerDAO), collateralAmount);
                    // Create CDP
                    makerDAO.createCDP(collateralAmount);
                }