Account Abstraction - Basic asccount abstraction implementation Crowdfunding - Basic implementation of real crowdfunding DAO Voting - Basic of defi stacking mechanism DAAP staking - Basic implementation of stacking mechanism NFT market - Basic implementation of nft market Payment Channel - Baic implementation of defi market Staking - My own implementation of stacking mechanism with custom ERC20 token Upgradeable Contracts - Open Zeppelin Upgradeable Contracts implementation (Transparent Proxy Pattern)