This report reviews the upgrade compatibility of Uniswap V3, a leading AMM with $1.64 billion in TVL. The protocol's architecture, including its non-fungible liquidity positions and concentrated liquidity, is robust but presents upgradeability risks. The review focuses on factory upgrades, pool implementation, router extensions, and governance parameter changes.Uniswap V3 employs a UUPS proxy for its factory, while pools are immutable, guaranteeing state integrity but requiring new deployments for certain upgrades. The periphery contracts, like the SwapRouter, are upgradeable, introducing potential storage collision risks. Cross-chain deployments share bytecode but require careful management of proxy admin contracts to avoid chain-specific failures.The overall compatibility risk rating is medium, with the primary concerns lying in the upgradeable periphery and potential factory-level storage changes. Identified attack vectors include UUPS proxy storage collisions in periphery contracts, factory upgrades breaking pool interfaces, and gas-limit regressions in periphery contracts. Cross-chain proxy admin mismatches and re-entrancy via new router hooks are also noted.Recommendations are categorized into critical, high, medium, and low priorities. Critical actions include enforcing storage-slot reservation maps, introducing a factory-upgrade guard, and adding cross-chain admin consistency checks. High-priority recommendations involve automated gas-usage regression testing and formal verification of immutable pool parameters.Medium-term enhancements focus on versioned interface registries and graceful degradation for L2 gas limits. Optional enhancements suggest publishing a developer upgrade guide and implementing the EIP-2535 Diamond pattern. The overall weighted risk score is 5.45, indicating a medium risk profile. The report emphasizes maintaining composability and decentralised governance while hardening upgrade compatibility.