Every pending transaction in the mempool is a statement of intent. Bots read it before it settles and front-run what's worth front-running.
The contract calls đđđ.đ´đ¸đĸđą(đĩđ°đŦđĻđ¯đđ¯, đĸđŽđ°đļđ¯đĩđđ¯, đ). That zero is 100% slippage tolerance. A frontrunner inflates the price, lets the swap settle, sells back at profit. A 10,000 USDC trade returns 1 ETH instead of 5.
đŗđĻđ˛đļđĒđŗđĻ(đĸđ¤đĩđļđĸđđđŽđ°đļđ¯đĩđđļđĩ >= đŽđĒđ¯đđŽđ°đļđ¯đĩđđļđĩ) lets the user set their worst acceptable price. If a bot moves the price outside that range, the swap reverts. The attacker burns gas for nothing.
The mempool stays public. Defense lives in the code, or it doesn't exist.