Why Modular Node Design Is Inevitable for Scaling

Full nodes must store the entire chain state, which grows at ~100 GB/year for major L1s. This creates an insurmountable hardware barrier for home validators, centralizing consensus.\n- Result: Fewer than 10,000 physical nodes secure most multi-billion dollar networks.\n- Trend: State size is a quadratic function of adoption; consumer SSDs cannot keep pace.

Modular design separates the execution layer (heavy computation) from the consensus layer (lightweight verification). This is the core thesis behind Celestia, EigenLayer, and rollup-centric architectures.\n- Benefit: Validators only need to sync consensus data, shrinking hardware requirements by >90%.\n- Benefit: Enables specialized execution environments (rollups, app-chains) to scale independently.

Even modular chains face a compute bottleneck at the block production layer. PBS, as pioneered by Ethereum post-merge, is a hardware-driven partition separating block proposal (requires high stake) from block building (requires high compute).\n- Driver: MEV extraction requires specialized hardware and real-time data (e.g., Flashbots).\n- Outcome: Creates a market for professional builders, preventing validator centralization from compute demands.

Splitting execution from consensus creates a critical dependency. An execution layer can halt, but the data layer remains live, creating a "zombie chain" scenario. Users see blocks but cannot transact. This is a fundamental attack vector that monolithic designs sidestep by guaranteeing atomic execution and settlement.

• Risk: Execution client bugs (e.g., early Optimism) can freeze the chain.
• Reality: ~30 min to hours of downtime possible during critical failures.

Modular stacks fragment block space and liquidity across rollups, validiums, and app-chains. This destroys cross-domain MEV arbitrage opportunities and cripples composability. Projects like dYdX moving to app-chains sacrifice liquidity for sovereignty, creating isolated pools that are easier to manipulate.

• Consequence: -60%+ effective liquidity for large trades crossing domains.
• Vector: Increases extractable value for searchers at the bridge layer (e.g., Across, LayerZero).

Data Availability layers like Celestia and EigenDA promote light clients and multi-client consensus for security. In practice, this creates a coordinated upgrade problem and reduces the economic cost of attacks. A monolithic chain like Solana has a single, massive stake to corrupt; corrupting a modular DA layer requires attacking far less value.

• Weakness: ~$1B staked on a DA layer secures ~$50B+ in rollup TVL.
• Result: Security is leased, not owned, creating systemic leverage.

In optimistic rollups, everyone must re-execute transactions to verify state. In ZK rollups, everyone must verify proofs. This verification cost is now a recurring tax paid in the base layer's native token (e.g., ETH for gas). As usage grows, so does this tax, creating a cost spiral that could outpace efficiency gains.

• Evidence: zkSync Era proof verification costs can spike to ~$50k per batch.
• Outcome: Long-term, the base layer captures all economic surplus, disincentivizing rollup builders.

Sovereign rollups and app-chains (e.g., Dymension RollApps, Fuel) own their settlement. This forces interoperability to move off-chain to bridges and messaging layers like LayerZero and Wormhole, which are trust-minimized but not trustless. The security of a $10B ecosystem now depends on $200M in bridge stake, creating a massive weak link.

• Attack Surface: Bridge hacks account for ~70% of all crypto theft.
• Complexity: Users now reason about N chain security + 1 bridge security.

Specialization breeds centralization. The most efficient sequencer, prover, or DA provider will dominate, recreating the web2 cloud oligopoly inside crypto. EigenLayer restakers, Espresso sequencers, and Celestia data providers are competing to become the centralized utility for thousands of chains. Modularity's promise of decentralization devolves into a few critical, too-big-to-fail services.

• Trend: >60% of rollups may use <3 shared sequencer providers.
• Irony: Replaces miner centralization with service provider centralization.

Running a full node today means executing, proving, storing, and networking in one binary. This creates an impossible resource burden for scaling.

• Cost: Storage for a full archive node exceeds 20TB and grows ~1GB/day.
• Performance: Synchronization can take weeks, a non-starter for institutional validators.
• Centralization: The hardware requirement curve pushes out all but the wealthiest operators.

Modular architecture decomposes the node into dedicated components: execution, settlement, consensus, data availability. Each can be optimized independently.

• Execution: Light clients & zk-proofs enable ~500ms state verification without full sync.
• Data: Celestia, EigenDA, and Avail provide $0.01/GB data availability, decoupling storage from compute.
• Proving: Risc Zero, SP1 create a competitive market for proof generation, driving cost to <$0.01 per transaction.

Operators will run specialized node types, not full stacks. This creates a liquid market for blockchain infrastructure services.

• Settlement Layer: Minimal nodes that only verify proofs and consensus (Fuel, Arbitrum).
• Execution Layer: Stateless verifiers that fetch state on-demand via Portal Network or Verkle tries.
• DA Layer: Light clients that sample data for fraud proofs or verify zk proofs of data availability.

A monolithic node cannot natively verify states of other chains. A modular, light client-based stack is essential for a multi-chain world.

• IBC: Relies on light clients for cross-chain trust, impossible with heavy full nodes.
• Omnichain: Protocols like LayerZero and Axelar require efficient verification of remote state.
• Intent-Based: Systems like UniswapX and CowSwap need fast, cheap verification across many domains, which only modular verification can provide.