If the core narrative of the previous bull market was a throughput arms race among “Ethereum killers,” the infrastructure focus of the current cycle has shifted toward a radically different paradigm—the modular blockchain. This philosophy advocates splitting the core functions of a blockchain—execution, settlement, consensus, and data availability—into separate, interchangeable, and specialized layers. It no longer tries to make a single chain handle all tasks, but instead constructs a decentralized network stack based on division of labor and collaboration, fundamentally reshaping the infrastructure skeleton of Web3.
Traditional monolithic chains, such as Ethereum L1, Solana, or BNB Chain, have the same set of validator nodes simultaneously handle transaction execution, consensus, and data storage. While this design provides a high degree of integration, it also creates significant performance bottlenecks. Whenever on-chain applications become active, every validator node in the network must download, execute, and store all transaction data, causing gas fee surges and processing delays. Modular approaches solve this dilemma by separating concerns: the execution layer is only responsible for computing transaction results, while the consensus and data availability layer ensures that the transaction ordering and data are correctly published and verifiable by anyone. This layered architecture allows each module to be independently optimized, enabling the execution layer to scale massively while retaining high security.
The greatest catalyst for the rise of the modular narrative has been the independence of the Data Availability (DA) layer. The data availability problem refers to the question: when a new block is proposed, can nodes be certain that the complete data behind the block has been made public, so that they can verify the absence of invalid transactions? Celestia, which launched its mainnet in 2023, became the first Layer 1 network specifically designed to provide data availability for other chains. It does not execute transactions but only orders the data and ensures its availability, using Data Availability Sampling (DAS) technology that allows light nodes to verify data integrity with a very high probability. Subsequently, competitors such as Avail and EigenDA entered the field, creating an emerging competitive market around data availability. Ethereum, in its own rollup-centric roadmap, is also positioning itself as the DA and consensus layer, with numerous Layer 2 solutions acting as execution layers.
The diversification of execution layers is equally dazzling. Under the modular framework, developers can easily deploy “appchains” or “rollups” customized for specific applications. For example, an on-chain gaming project can optimize its own execution layer for low latency and high-frequency interactions, while a decentralized derivatives exchange can customize sequencing rules to resist front-running. Ultimately, these execution layers only need to post their transaction data to a DA layer and have a settlement layer such as Ethereum handle disputes and bridging. This means that developers no longer need to compromise with the resource contention and development limitations of a general-purpose chain; the era of “owning one’s own chain” for Web3 applications has finally arrived, without requiring the enormous cost of maintaining a validator network.
Of course, modularity does not come without costs. Fragmentation is the foremost challenge it faces. When the number of execution layers explodes, liquidity becomes split among different rollups and appchains, making cross-chain interactions complex and expensive. Although cross-chain communication protocols and shared sequencer solutions are working to alleviate this issue, the smoothness of user experience and the instantaneity of asset transfers still fall far short of the ideal. Additionally, the security models of various layers within the modular stack are not uniform; some DA layers may rely on smaller validator sets, with security assumptions that differ from traditional public chains, requiring stratified assessments of risks across different layers.
It is worth noting that the modular design philosophy is being pushed to further extremes. “Modular execution layers” like Fuel Network even deconstruct execution further into computation and verification, optimizing parallel transaction processing. Meanwhile, the concept of “sovereign rollups” asserts that the execution layer possesses governance rights independent of the settlement layer, allowing it to autonomously decide on upgrades and forks. This composability not only brings flexibility at the technical level but also sparks innovative experiments in governance structures and economic models.
In summary, modular blockchain is not a victory announcement for a particular star chain, but rather a collective ideological liberation movement about how to build an open, interoperable, and scalable decentralized network. It pushes the blockchain technology stack from vertical integration toward horizontal layering, enabling developers to select the components best suited to their needs much like assembling LEGO bricks. As competition among data availability layers intensifies, cross-chain interoperability protocols mature, and development tools continue to simplify, a multi-chain universe composed of countless specialized chains is gradually taking shape. For readers who follow the evolution of industry infrastructure over the long term, modularity represents a structural trend that transcends the rise and fall of individual projects, and it is very likely to define the foundational architectural paradigm for decentralized applications in the coming decade.