At Spire, we're building the Based Stack — letting apps spin up their own based rollup L2s / appchains. As rollup ecosystems evolve, a new frontier is emerging — L3s built on top of existing L2s. This post explores how Spire’s approach, which combines shared settlement and coordinated sequencing, can extend beyond L2s, enabling rollups to function as synchronous execution environments. This architecture extends beyond traditional rollup sequencing models, offering faster, customizable intra-b...