Coinbase is a centralized exchange. Of course it runs in a SQL db or whatever. They only need to touch the chain when settling inflows/outflows.
But something like Uniswap: https://app.uniswap.org/#/swap is fully on-chain. Every trade happens on chain, because the application is an immutable smart contract liquidity protocol, called an AMM, or automated market maker.
But something like Uniswap: https://app.uniswap.org/#/swap is fully on-chain. Every trade happens on chain, because the application is an immutable smart contract liquidity protocol, called an AMM, or automated market maker.
It does as much, if not more, volume than Coinbase ($1.98B in last 24H): https://info.uniswap.org/#/