Modular Blockchain Explained: Deconstructing Traditional Monolithic Chains and Redefining the Web3 Architecture

1. What is a Modular Blockchain? Understanding the Fatal Flaws of Traditional Monolithic Chains

Traditional Bitcoin, early Ethereum, and Solana all belong to monolithic blockchains, where all four core functions are packed into a single network: executing transactions, achieving consensus ordering, storing all raw transaction data, and processing asset final settlements, all handled by the same group of nodes.

This "one chain does it all" model is inherently contradictory, directly colliding with the blockchain trilemma: security, decentralization, and scalability cannot be simultaneously addressed.

To achieve high TPS, the hardware requirements for nodes must be raised, sacrificing decentralization;

Pursuing full node validation across the network necessitates compressing block capacity, leading to skyrocketing fees during congestion;

The underlying code is highly coupled, and modifying any aspect of consensus, scalability, or storage requires a hard fork across the entire network, resulting in extremely low iteration efficiency.

Modular Blockchain is a complete overhaul of this architecture: it decouples the four core functions originally bound to a single chain into four independent, pluggable layers, each with its own responsibilities and collaborative roles. The four layers are: Execution Layer, Consensus Layer, Data Availability (DA) Layer, and Settlement Layer.

2. Simplified Explanation of the Four Layers of Modularity

1. Execution Layer: The On-Chain Computing Workshop, Handling Only Transactions

Positioning: The front end of user interaction, responsible for packaging transfers, executing smart contracts, and updating on-chain account statuses, commonly referred to as ZK-Rollup, OP-Rollup, and sovereign application chains.

It focuses solely on computation, without the need to store massive amounts of raw data, achieve consensus across the network, or handle asset verification, directing all computational power towards TPS optimization, easily achieving processing speeds of thousands of transactions per second.

2. Consensus Layer: The Global Time Judge

It does one thing: sorts the batches of transactions submitted by the execution layer and produces blocks, achieving a unified consensus among all network nodes on the order of transactions, without participating in contract computations or storing complete transaction details.

A dedicated DA chain will merge consensus and data availability into one layer, further simplifying the architecture.

3. Data Availability Layer (DA): The On-Chain Public Bulletin Board, the Core Infrastructure of Modularity

DA is the security foundation of the modular system, with the core function of permanently storing all raw transaction data from the execution layer, ensuring that any node or person can download and verify complete transaction records at any time, preventing the manipulations of sorters and the concealment of transaction data.

In monolithic chains, DA, execution, and consensus are tightly bound together, making scalability extremely costly; the modular era introduces dedicated DA public chains that provide low-cost data storage services, notably Celestia and Avail, which are key focuses of this discussion.

4. Settlement Layer: The Final Notary, Ensuring Asset Security

Responsible for verifying proofs submitted by the execution layer (fraud proofs / zero-knowledge proofs), handling cross-layer asset transfers, resolving on-chain disputes, and providing finality for transactions. Currently, Ethereum serves as the mainstream settlement layer in the industry, with all L2 and sovereign Rollups ultimately anchoring assets to the Ethereum mainnet for verification.

3. Monolithic Chains vs. Modular Blockchains: A Comprehensive Comparison of Advantages and Disadvantages

(1) Advantages and Disadvantages of Monolithic Public Chains

Advantages

• Simple architecture, no multi-layer cross-layer interactions, intuitive for short-term development;
• A single network with a unified security model, short asset settlement processes, and no multi-layer trust accumulation;
• A native and complete ecosystem, with fewer issues related to cross-layer compatibility and communication.

Fatal Flaws

• Severe functional coupling, extremely low scalability ceiling, congestion inevitably raises Gas fees;
• High upgrade costs, modifying any underlying function requires a hard fork across the entire network;
• Extremely high development barriers, building a monolithic public chain from scratch requires self-developing the entire suite of consensus, storage, and execution, with a timeline exceeding one year and costs in the millions for manpower and audits;
• Resource wastage: nodes must handle contract computations, store all blocks, and participate in consensus, leading to a polarized hardware threshold and a continuous decline in decentralization.

(2) Advantages and Disadvantages of Modular Blockchains

Core Advantages

• Layered specialization optimization, breaking through scalability bottlenecks: the execution layer focuses on maximizing TPS, the DA layer concentrates on compressing storage costs, and the settlement layer ensures security, with the four layers not dragging each other down;
• Pluggable components with high customization: developers can freely combine execution environments, DA layers, and settlement layers as needed;
• Significantly lowers the development threshold for public chains, eliminating the need to build the entire underlying system from scratch;
• Flexible iteration: upgrading a specific layer independently without requiring a hard fork across the entire network, accelerating innovation;
• Sovereignty separation: the upper execution chain possesses independent governance, upgrade, and forking rights, free from constraints imposed by the underlying DA or settlement chains, known as "sovereign Rollups";
• Security layering: the dual-layer verification of the underlying DA and settlement significantly raises the cost of malicious actions compared to monolithic chains.

Existing Shortcomings

• Multi-layer architecture introduces interaction complexity, requiring supporting toolchains for cross-layer communication and proof synchronization;
• Multi-chain layering introduces multiple trust assumptions, and incorrect selections can introduce additional security risks (e.g., opting for centralized third-party DA);
• Early modular infrastructure tools are not well-developed, and adapting niche execution environments can be labor-intensive;
• Multi-layer networks accumulate staking and Gas consumption, leading to multi-layer fee accumulation costs.

4. Mainstream Dedicated Data Availability (DA) Chains Explained: Celestia and Avail

The DA layer serves as the foundational base of the modular system, specifically for data publishing and storage, executing no smart contracts and maintaining no account balances, referred to in the industry as a "state-less underlying network."

1. Celestia: The Pioneer of Modular DA

The first dedicated modular data availability chain in the industry, setting the standard for modular narratives.

Core Technology: Data Availability Sampling (DAS), allowing light nodes to verify data completeness through random sampling without needing to download complete blocks, significantly lowering the operational threshold for nodes and enhancing decentralization;

Namespace Merkle Tree (NMT): Isolating data storage for different Rollups and application chains, preventing interference and improving verification efficiency;

Underlying Consensus: Tendermint BFT, enabling rapid block production and immediate consensus;

Core Positioning: Providing low-cost, high-throughput data storage for all sovereign Rollups and ZK/OP Layer 2s, with upper chains having complete sovereignty and customizable virtual machines and governance rules;

Applicable Scenarios: Vertical application chains, gaming Rollups, RWA dedicated chains, and lightweight ZK Layer 2s.

2. Avail: Lightweight High-Performance DA Layer

A next-generation modular data availability network that competes with Celestia, focusing on lower storage costs and higher data throughput.

Technical Features: Optimized erasure coding schemes, higher block data compression efficiency, and improved verification experience for mobile and light nodes;

Differentiated Advantages: Natively compatible with the Ethereum ecosystem, ZK Stack, and OP Stack, making it more friendly for Ethereum-based Rollups;

Security Mechanism: Built-in data fraud detection, enabling quick network penalties in case of data loss or tampering;

Positioning: Targeting large-scale, high-frequency small applications, AI on-chain interactions, and massive NFT minting scenarios with high data demands.

Supplement: Ethereum Blob (EIP-4844) Native DA

Ethereum itself also undertakes DA functions, relying on Blob data blocks to store L2 transaction data, offering the highest security but at a higher storage cost than Celestia and Avail; mainstream L2s (Arbitrum, zkSync) that prioritize extreme security prefer Ethereum's native DA, while application chains seeking low-cost, high-throughput solutions opt for external DA from Celestia/Avail.

5. How Modular Architecture Significantly Lowers the Development Threshold for Public Chains: From "Self-Developed Chains" to "Building Blocks"

Traditional monolithic public chain development requires teams to tackle consensus algorithms, distributed storage, P2P networks, virtual machines, and scalability solutions from scratch, with development cycles of 10 to 18 months and extremely high audit and security costs, making it unaffordable for most startups. The modular architecture fundamentally rewrites the development paradigm:

Direct Reuse of Underlying Infrastructure, No Need to Reinvent the Wheel

Developers do not need to self-develop DA layers or consensus layers; they can directly access the data publishing services provided by Celestia and Avail; settlements can directly reuse Ethereum's security, eliminating the need for underlying security development. They only need to develop their own execution layer (ZK/OP Rollup, dedicated application chain), reducing development workload by over 70%.

Mature Standardized One-Click Chain Deployment Framework

OP Stack, Polygon CDK, Cosmos SDK, and Rollup as a Service (RaaS) provide a complete set of tools ready to use:

• Want to create an EVM-compatible chain: Deploy OP Layer 2 with one click using OP Stack;
• Want to build a high-performance ZK chain: Quickly set up a zkEVM execution layer with Polygon CDK;

The entire process is shortened from one year to 2 to 8 weeks, with labor costs reduced by 85%.

Flexible Combinations Based on Demand, Controlling Costs and Security

Teams can freely combine layers based on their track:

• Financial and large asset tracks: Ethereum DA + Ethereum settlement for extreme security;
• Chain games and small payment tracks: Celestia/Avail low-cost DA to control fees;

No need to sacrifice performance or cost due to adapting to a single monolithic chain.

Sovereignty Independence, Governance Unconstrained by the Underlying Layer

Sovereign Rollups built on external DA possess independent tokens, governance rules, and contract upgrade rights, free from governance compromises imposed by Ethereum or underlying DA chains, suitable for creating vertically independent ecosystems (derivative chains, AI Agent chains, and physical RWA chains).

Shared Security Costs, Reducing Audit Pressure

The underlying security of the DA layer and settlement layer is collectively guaranteed by large network nodes, with new projects only needing to audit their own execution layer contracts, eliminating the need for significant investments in underlying consensus and storage security audits, greatly reducing pre-launch security expenditures.

6. Summary of the Development of the Modular Blockchain Industry

Modularity is not a simple scalability patch but a long-term evolutionary direction for the underlying architecture of blockchain. Ethereum, centered on the settlement layer, with dedicated DA chains like Celestia and Avail providing the data foundation, and ZK/OP Rollups serving as diverse execution layers, collaboratively form a complete Web3 infrastructure network.

In contrast to the monolithic chain's "omnipotent yet mediocre" approach, modularity, through specialized division of labor, balances scalability performance, decentralization, and development freedom, addressing the long-standing cost and threshold issues that have constrained the large-scale implementation of public chains. In the future, the vast majority of specialized chains and application Rollups in vertical tracks will be built on modular architecture, while monolithic chains will focus more on extremely simple, low-interaction niche scenarios.

Disclaimer: This content is provided for general branding and informational purposes only and doesn't constitute financial, investment, legal, or tax advice. Any events, rewards, online events, or related information mentioned herein should not be considered a recommendation, solicitation, or invitation to purchase, sell, trade, or otherwise deal in any crypto assets or to use any services. Crypto assets are highly volatile and may result in loss. WEEX services and online events may not be available in all regions and are subject to applicable laws, regulations, and eligibility requirements. You are responsible for ensuring that your use of WEEX services complies with local laws and for carefully assessing the risks before participating in any crypto-related activities.