Decentralized Sequencer

The evolution of scalability solutions on Ethereum began with State Channels, followed by Sidechains and Plasma. While these solutions addressed scalability, they came with complexities and limitations. Rollups, specifically Optimistic Rollups and zk-Rollups, emerged as promising Ethereum Layer 2 scaling solutions.

A sequencer plays a crucial role in managing and ordering transactions. In a Layer 2 scaling solution, transactions are processed off-chain to improve scalability, but there is a need for a mechanism to keep track of the correct order of these off-chain transactions before they are finalized on the main blockchain.

The sequencer acts as a coordinator or orderer in the Layer 2 network. It is responsible for collecting and organizing transactions from users or participants before submitting them to the main blockchain. This helps ensure that the transactions are executed in the correct sequence, maintaining the integrity and consistency of the overall transaction history.

However, the challenge with a centralized sequencer is that it introduces a potential single point of failure and centralization risk. If the sequencer is compromised or experiences downtime, it can impact the entire Layer 2 network.

To address these concerns, Metis is poised to become the first Ethereum rollup to decentralize its sequencer, addressing security concerns and promoting community involvement. This shift enables features like seamless sequencer rotation, improved network stability, and revenue sharing through a Proof-of-Stake Sequencer Pool.