We employ a four-phase audit methodology tailored for upgradeable systems: 1) Architecture Review of the proxy pattern (UUPS, Transparent, Beacon) and upgrade governance. 2) Manual Code Review focusing on storage collisions, initialization vulnerabilities, and function selector clashes. 3) Automated Analysis using Slither and custom tools to detect proxy-specific risks. 4) Test Suite & Integration Review to verify upgrade simulations and admin key security. This process is derived from securing $500M+ in TVL across 50+ proxy-based projects.