Vitalik Buterin has recently shared his thoughts on the current biggest challenge for Ethereum. Despite advancements in scaling territory, Ethereum still has a lot to cover in order to become a better network from the viewpoint of users. There are two main approaches to scaling: layer-1 sharding and layer-2 solutions, like rollups. Both methods can be broken down into simple "we are handling more transactions." The underlying tech is similar, as both of them use ZK-SNARKs to verify transactions on the network and Data Availability Sampling for data availability. The key difference there is in managing and implementation.