Author: yyy｜Chain Hill capital Introduction In recent years, with the rapid development of the Ethereum network, the proliferation of on-chain transactions has overloaded, and on-chain transactions have become slow and expensive. With both the Defi wave in summer 2020 and the NFT frenzy last year, the congestion of the Ethereum network was further exacerbated, which seriously limits the large-scale development of Ethereum ecosystem. Consequently, the scaling issue of Ethereum has attracted th...