Sandwich Complexity Model

The sandwich complexity model is a design philosophy in Ethereum protocol development that advocates for maintaining a clear separation between the core consensus layer and application-level layers. This principle suggests that the protocol should remain simple and focused on consensus and settlement, while allowing complexity to be pushed to higher layers where application-specific logic resides. By keeping the base layer lean, the model enables easier protocol upgrades, reduces bugs in critical infrastructure, and makes it simpler for node operators to run the network. Complexity in applications can be managed independently without risking the entire blockchain's integrity or security. Example: Ethereum's rollup-centric roadmap exemplifies this model, intentionally keeping Layer 1 simple (handling settlement and data availability) while delegating transaction execution and ordering to Layer 2 solutions like Arbitrum and Optimism where complexity naturally resides. Why it matters for blockchain technology: This design principle reduces attack surface on critical infrastructure, improves base-layer stability, enables faster consensus upgrades, and allows innovation to flourish at application layers without compromising network security or accessibility.

Category: blockchain technology

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