Immutable code has historically been a feature of blockchain development, not a bug. Once deployed to mainnet, a smart contract cannot be modified. This immutability guarantees that users interact with exactly what they audited, but it also creates a harsh reality: mistakes are permanent, and new functionality cannot be added. The proxy pattern emerged to solve this problem by decoupling logic from state, allowing developers to upgrade contract behavior without losing historical data or breaking user integrations. However, proxy patterns introduce their own class of vulnerabilities. Storage layout collisions between proxy contracts and their implementations, version drift across upgrade paths, and subtle state corruption bugs can emerge only after multiple upgrades in production. These risks are not theoretical—they have caused millions in losses across deployed protocols.…