a16z Crypto, a venture capital fund, led a $28m Series B round in Espresso Systems, a software development company, with participation from Polygon. “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. Shared sequencing enables rollup users to regain the experience of being on one Ethereum chain,” Ben Fisch, Espresso Systems CEO.