Proxy Contract Pattern
The proxy contract pattern is a structural design used in blockchain development to enable upgradability by separating the contract logic from the contract state. It consists of a proxy contract that holds the state and a separate implementation contract that contains the actual code logic.
When a user interacts with the protocol, the proxy delegates the call to the implementation contract using low-level delegatecall instructions. This allows developers to deploy a new implementation contract and update the proxy to point to it, effectively upgrading the system without migrating data.
However, this pattern introduces significant risks, such as storage collisions between the proxy and implementation or unauthorized logic changes. It is a fundamental mechanism in modern DeFi, but it shifts trust from code immutability to administrative governance.