Modular blockchain stacks are separating execution, data availability and settlement into distinct infrastructure layers

Blockchain architecture is increasingly shifting from monolithic chains toward modular stacks where execution, data availability (DA) and settlement are handled by specialized layers.

In this model:

• rollups (Optimism, Arbitrum) externalize execution
• Ethereum acts as a settlement/consensus anchor
• dedicated DA networks like Celestia provide scalable data availability

The separation allows each layer to optimize independently — execution environments for throughput and VM design, DA layers for bandwidth and sampling, and settlement layers for consensus security.

This mirrors the layered evolution of internet infrastructure, where compute, storage and networking decoupled to scale independently.

As rollups proliferate, DA capacity becomes a bottleneck resource and settlement layers become security hubs rather than execution engines.

Full breakdown: https://btcusa.com/modular-blockchain-stack-how-data-availability-execution-and-settlement-layers-are-reshaping-crypto-infrastructure/

Curious how people here see the modular stack evolving technically — especially around DA sampling, shared sequencing and cross-rollup composability