What Is a Blockchain Sequencer? It Sits Between Ethereum and Layer-2 Networks Like Coinbase’s Base

A criticism of the setup is that today’s rollup sequencers are typically run by “centralized” entities, and thus represent single points of failure, potential vectors for transaction censorship, or possibly a choke point if authorities ever chose to shut it all down. Coinbase, for example, runs the sequencer for its new Base blockchain, a role that could produce an estimated $30 million of net revenue annually, based on estimates by the analysis firm FundStrat.