LAYER 2 SEQUENCERS

A sequencer refers to a mechanism or component within a blockchain protocol that helps to establish the order of transactions or other operations. It plays a crucial role in maintaining the consistency and integrity of the blockchain.

Layer 2 sequencers are responsible for organizing transactions on a L2 protocol to make sure transactions are in correct order.

You need to remember 2 things:

• First-come, first-served basis, which means priority is given to transactions submitted earlier.

•Organizing transactions based on gas fees, which means priority is given to transactions with higher fees.

TYPES OF L2 SEQUENCERS

• DECENTRALIZED
Decentralized sequencers use a network of nodes to carry out their responsibilities (like Metis). Decentralized sequencers have the advantage of not having a single point of failure.

• CENTRALIZED
Centralized sequencers are the most common type and are available in L2 networks (like Base, Arbitrum & Optimism). Centralized sequencers are beneficial in offering near-instant finality.

• SHARED
Shared sequencers act almost like a decentralized sequencing third party for several rollup networks (Astria & Espresso). Shared sequencing enables interoperability between L2 rollups.