MegaETH is an advanced blockchain execution platform designed to offer exceptional performance and efficiency for decentralized applications as well as high-throughput workloads. To reach this goal, MegaETH unveils an innovative state trie architecture that efficiently scales to terabytes of state data while maintaining low I/O costs. The platform adopts a write-optimized storage backend, replacing conventional high-amplification databases, which guarantees rapid and consistent read and write latencies. It also employs just-in-time bytecode compilation to remove interpretation delays, achieving speeds close to native code for compute-heavy smart contracts. Additionally, MegaETH utilizes a dual parallel execution model; block producers apply a versatile concurrency protocol, while full nodes leverage stateless validation to enhance parallel processing capabilities. For seamless network synchronization, MegaETH incorporates a specialized peer-to-peer protocol with compression methods that enable nodes with limited bandwidth to remain synchronized without sacrificing throughput. This combination of features positions MegaETH as a leading solution for the future of decentralized applications.