This document discusses the challenges of implementing a non-fungible token (NFT) marketplace. It begins with definitions of key terms like NFTs, smart contracts, and token standards. It then outlines features of NFT marketplaces like auctions, creating NFTs, and connecting wallets. The major challenges discussed are limitations of standards like ERC-721 and ERC-1155, high gas fees on networks like Ethereum, and limitations of networks regarding transaction costs, throughput, and consensus protocols. In summary, developing an efficient and usable NFT marketplace requires addressing challenges around standards, costs, and blockchain capabilities.