[Vitalik Buterin: Layer 2-centric ecosystem faces coordination challenges] Ethereum co-founder Vitalik Buterin recently wrote that although "Layer2" and "sharding" are seen as two opposing strategies for blockchain expansion, in fact, the expansion methods of the two are exactly the same, and the main difference lies in the responsible party for construction and updating and its autonomy. He emphasized that the Layer2-centric ecosystem has technically achieved sharding, and this autonomous and innovative sharding has great potential, but it also faces key challenges such as coordination. He believes that in order to make the Layer2-centric ecosystem successful, it is necessary to understand and solve these challenges in order to maximize the advantages of the Layer1-centric ecosystem and get as close as possible to having the best features of both.