“Rollups have enriched the greater Ethereum ecosystem with horizontal scalability and a diversity of execution environments, but at the expense of fragmentation—apps across rollups do not have the same shared liquidity and interoperability as apps on the Ethereum L1,” Ben Fisch, CEO of Espresso Systems, said in an interview with CoinDesk over email. “Shared sequencing enables rollup users to regain the experience of being on one Ethereum chain.”