Caldera is a rollup platform on Ethereum that enables horizontal scaling and interoperability between rollups. Instead of optimizing a single blockchain, Caldera allows projects to launch customizable rollups while maintaining Ethereum's security and decentralization. The platform introduces the Metalayer, a unifying layer designed to connect rollups across Optimistic and Zero-Knowledge (ZK) frameworks. This enables coordination, communication, and resource sharing while preserving the distinct features of each rollup.