The article explores the current developments and future trends of the execution layer, settlement layer, and aggregation layer in the modular blockchain stack within the cryptocurrency field. Although there have been many innovations in the data availability (DA) and ordering layers, the execution and settlement layers have only recently begun to receive attention. The article points out that while the shared sequencer space is highly competitive, the execution and settlement layers remain underexplored. Layer N, as a flexible and customizable execution layer, leverages the Move language and BlockSTM technology to improve throughput. The article also discusses the design of proof aggregation, a new architecture that can aggregate and settle between different proof systems, thereby enhancing efficiency and reducing costs. Finally, the article predicts that these innovations will bring better applications and development experiences to users.