What are Shared Sequencers?
Shared Sequencers are tools and services that manage transaction ordering and execution on layer 2 blockchain networks, particularly rollups. These sequencers collect user transactions, order them, and submit batches to the underlying layer 1 blockchain. They help improve scalability and reduce latency by handling transaction sequencing off-chain while maintaining security guarantees through the layer 1. Tools in this category include sequencer operators, transaction ordering services, and batch submitters. The primary users are developers building on layer 2 solutions who need reliable and efficient transaction ordering without running their own sequencer infrastructure. Key characteristics include low-latency transaction processing, fair ordering mechanisms, and integration with layer 1 consensus. Shared Sequencers often operate in a semi-centralized manner, making trust and performance critical factors. This category relates closely to layer 2 infrastructure and rollup operator tools. Developers should consider shared sequencers when building or deploying dapps on rollups that rely on external sequencers for transaction ordering and batch submission.