UUPS

Universal Upgradeable Proxy Standard (EIP-1822) — a proxy pattern where the upgrade authorisation logic lives in the implementation contract itself, rather than in the proxy. Lower gas per call than transparent proxies, but a bug in any implementation's upgrade-authorisation logic can permanently break upgradeability. Modern OpenZeppelin default. Implementations must call `_disableInitializers()` in their constructor to prevent the implementation itself from being initialised and bricked.