As a blockchain architect studying modular design, I want to explain the modular blockchain thesis and why it’s the future of scalability.
The Modular Thesis:
Traditional blockchains (Bitcoin, Ethereum) are monolithic:
- Execution (running transactions)
- Data availability (storing transaction data)
- Consensus (agreeing on order)
- Settlement (final state)
All happen on ONE chain.
The Problem:
Trilemma: Can’t optimize all three:
- Decentralization
- Security
- Scalability
Pick two.
The Modular Solution:
Separate concerns into specialized layers:
Layer 1: Settlement (Ethereum)
- Final source of truth
- Dispute resolution
- Security anchor
Layer 2: Execution (Rollups)
- Run transactions off-chain
- Post compressed proofs to L1
- 100x cheaper than L1
Layer 3: Data Availability (Celestia, EigenDA)
- Store transaction data
- Not execution, just storage
- 99% cheaper than Ethereum calldata
Layer 4: Consensus (varies)
- Each layer has own consensus
- Doesn’t need to be coupled
Why This Works:
Specialization beats generalization.
Ethereum trying to do everything:
- 15 TPS
- $5-20 per transaction
- 12s finality
Modular stack (Arbitrum + Celestia + Ethereum):
- 10,000+ TPS (rollup capacity)
- $0.01 per transaction
- 1-2s finality (on rollup)
Key Innovation: Data Availability Layers
This is THE breakthrough.
Before: Rollups posted data to Ethereum (expensive)
After: Rollups post data to Celestia/EigenDA (99% cheaper)
Celestia:
- First modular DA layer
- Data availability sampling (light nodes verify without downloading all data)
- $0.81/MB vs Ethereum’s $100/MB
EigenDA:
- Uses Ethereum restaking
- Even cheaper than Celestia
- 100+ rollups committed
Ethereum Blobs (EIP-4844):
- Native blob space on Ethereum
- Cheaper than calldata
- But still 10x more expensive than Celestia
The Tradeoffs:
Monolithic (Solana):
Atomic composability (everything on one chain)- Simple mental model
- Unified liquidity
Hard to scale beyond hardware limits- Less customizable
Modular (Ethereum rollup ecosystem):
- Unlimited scalability (spawn more rollups)
- Customizable (each rollup optimized)
- Ethereum security
- Fragmented liquidity
- Complex UX (bridging)
- No atomic composability across rollups
Real-World Adoption:
2023:
- Celestia launches mainnet
- EIP-4844 activates on Ethereum
- 20+ rollups live
2025:
- 50+ rollups
- $40B TVL
- Celestia securing 40+ rollups
- EigenDA launching
Use Cases:
When to use modular:
- DeFi (security-critical, needs Ethereum settlement)
- Payments (needs scale)
- Enterprise (needs customization)
When to use monolithic:
- Gaming (needs low latency, atomic composability)
- High-frequency trading (needs atomic composability)
- Consumer apps (needs simple UX)
The Future:
2027 Prediction:
- 100+ rollups
- Celestia + EigenDA dominate DA
- Ethereum as settlement layer
- 10M+ TPS total capacity
- $100B+ TVL on rollups
Bottom line: Modular is winning because specialization beats monolithic design for scalability.