Optimistic Rollups: Metis

In the blockchain space, it is a well-known fact that scaling is a tough challenge to address. A typical reference when discussing challenges associated with scaling would be the scalability trilemma coined by Vitalik Buterin. Vitalik Buterin’s post regarding the scalability trilemma referenced sharding: a mechanism that shows great potential but is highly difficult to implement. The challenges and trade-offs for sharding have been covered in a prior piece. However, rollups have been touted as a simpler and more realistic approach to scaling blockchains.

Rollups, which essentially batch on-chain transactions instead of executing them one by one on the base layer, are proposed to allow blockchains to scale without significant trade-offs in any particular aspect of the scalability trilemma. In another post by Vitalik, he conceded that rollups “are poised to be the key scalability solution for Ethereum for the foreseeable future.”