Layla Zulfa
The Ethereum Foundation’s Platform team has articulated a refined "North Star" vision, emphasizing the scaling of Ethereum as a cohesive, interconnected system designed to foster confident adoption by a global user base. This strategic update re-evaluates the foundational relationship between Ethereum’s Layer 1 (L1) blockchain and the burgeoning network of Layer 2 (L2) solutions, aiming to leverage the distinct strengths of each layer to construct the most compelling and robust platform for all participants. The outlined perspective acknowledges existing successes while committing to ongoing experimentation and iteration with the broader community to validate future directions.
The Evolution of Ethereum’s Scaling Strategy
For years, the Ethereum network has grappled with the inherent "blockchain trilemma," a concept suggesting that a decentralized system can only achieve two of three properties at any given time: decentralization, security, or scalability. Ethereum’s L1 prioritizes decentralization and security, which, while crucial for its integrity and trustlessness, historically led to limitations in transaction throughput and higher gas fees during periods of high demand. This challenge spurred the initial drive for scaling solutions.
Approximately five years ago, a pivotal shift occurred with the formal proposal of a "rollup-centric roadmap" within the Ethereum community, notably discussed on platforms like Ethereum Magicians. This roadmap posited that instead of attempting to scale the L1 directly to handle all transactions, Ethereum would offload much of the transaction execution to specialized L2 networks, known as rollups, while the L1 would serve as the ultimate settlement and data availability layer. This vision marked a strategic pivot, recognizing that direct L1 scaling alone might compromise Ethereum’s core tenets of decentralization and security.
Since that seminal proposal, the landscape has transformed dramatically. An expansive ecosystem of L2 chains has blossomed around Ethereum L1, each offering varying degrees of decentralization, security inheritance, and customization. These include highly integrated solutions like Stage 2 rollups, which inherit full decentralization guarantees from L1, to more specialized chains like validiums and prividiums that adopt a subset of security properties, and even those that primarily leverage the Ethereum Virtual Machine (EVM) standard without direct L2 integration. Many of these projects began as independent ventures, gradually deepening their integration with Ethereum L1 as the technology matured.
The maturation of technologies underpinning L2s, such as cryptographic proofs (especially Zero-Knowledge proofs) and data availability layers, has been a key driver. Innovations like EIP-4844 (proto-danksharding), scheduled for implementation in the upcoming Dencun upgrade, are specifically designed to reduce L2 transaction costs by providing dedicated space for rollup data on the L1, significantly enhancing their scalability. This technological evolution has not only clarified the competitive advantages of L2s but also underscored their immense value proposition for users seeking faster, cheaper transactions without sacrificing the security assurances of Ethereum.
A Refined Model for L1 & L2 Interplay
The Ethereum Foundation (EF) and the wider ecosystem now acknowledge the necessity of updating the established model for the L1-L2 relationship. The original rollup-centric roadmap was a groundbreaking conceptual framework, but the practical realities and technological advancements of the past half-decade demand a more nuanced and formalized understanding. L2s have evolved into robust ecosystems with their own communities, liquidity, and development trajectories. Concurrently, the L1 scaling roadmap, particularly regarding shard chains and data availability, has come into sharper focus, demonstrating a clear path to significant L1 scalability while preserving decentralization.
The core of this clearer vision posits a symbiotic relationship where Ethereum L1 acts as the unshakeable foundation, and L2s provide the diverse, scalable superstructure. This model is not merely about offloading transactions but about creating a mutually reinforcing network where each layer enhances the other’s utility and resilience.
Distinct Roles and Mutual Benefits
Ethereum L1 remains the bedrock of the decentralized economy, revered for its unparalleled adoption, developer engagement, decentralization, resilience, and economic "hardness." It stands as the undisputed heart of the Decentralized Finance (DeFi) ecosystem, boasting the deepest liquidity pools and serving as the ultimate arbiter of state. The ongoing development of ZK technology, far exceeding initial expectations due to concerted efforts across the ecosystem, promises to scale Ethereum L1 by several orders of magnitude in the coming years, all while upholding its core values.
However, even a vastly scaled Ethereum L1 cannot unilaterally cater to the myriad and specialized demands of a truly global on-chain economy. This is where L2s become indispensable, offering:
- Specialized Execution Environments: L2s can be tailored for specific use cases, such as gaming, high-frequency trading, or privacy-focused applications, optimizing their parameters for those needs (e.g., faster block times, different gas fee structures, specific data availability guarantees).
- Customization and Flexibility: They allow for experimentation with new features, governance models, or virtual machines that might be too risky or complex to implement directly on the main L1 chain, fostering innovation at the fringes of the ecosystem.
- Cost-Effectiveness and Speed: By batching transactions off-chain and only posting a summary to L1, L2s drastically reduce transaction costs and increase processing speed, making blockchain interactions accessible to a wider user base and enabling micro-transactions.
- Economic Differentiation: L2s can explore alternative economic models, tokenomics, or fee structures that cater to their specific user bases or application types, without compromising the economic security of the L1.
Why Chains Choose to Be Ethereum L2s:
The decision for other chains to integrate as L2s on Ethereum is rooted in compelling advantages:
- Inherited Security and Decentralization: By settling transactions on Ethereum L1, L2s inherit its robust security guarantees and unparalleled decentralization, mitigating the risks associated with bootstrapping their own validator sets or security models. This is a crucial differentiator from independent sidechains.
- Access to Deep Liquidity: Tapping into Ethereum’s vast liquidity pool is a significant draw. Users and applications can seamlessly move assets between L1 and various L2s, facilitating composability and market depth.
- Developer Mindshare and Tooling: The Ethereum ecosystem boasts the largest and most vibrant developer community, along with a mature suite of development tools (e.g., Hardhat, Truffle, Ethers.js, Web3.js). Building as an L2 allows projects to leverage this established infrastructure and talent pool.
- Interoperability and Composability: L2s within the Ethereum orbit are inherently designed for a degree of interoperability, enabling seamless asset and message passing. This fosters a cohesive multi-chain environment where applications can interact across layers.
- Network Effects: Being part of the Ethereum ecosystem provides access to its immense user base, brand recognition, and a strong network effect that is difficult for nascent, independent chains to replicate.
How Ethereum L1 Benefits from L2 Relationships:
The relationship is unequivocally bidirectional. Positioning Ethereum L1 at the core of this expanding network of L2s reinforces its unique and indispensable role in the on-chain economy:
- Enhanced Demand for L1 Blockspace: As L2s process more transactions, they periodically commit their state roots and batches of transactions back to L1 for final settlement and data availability. This consistent demand for L1 blockspace drives transaction fees, which accrue to L1 validators (and historically, miners), enhancing the network’s economic security. The success of L2s directly translates to increased utility and value for the L1.
- Increased Network Economic Bandwidth: By offloading computation, L2s allow Ethereum L1 to focus on its core strengths: data availability, consensus, and finality. This dramatically expands the overall economic bandwidth of the Ethereum ecosystem, enabling a far greater volume of economic activity than L1 could handle alone.
- Reinforcement of ETH’s Value Proposition: ETH serves as the native asset for gas fees on L1 and is often used as the base currency for L2s or for bridging liquidity. The growth of the L2 ecosystem, therefore, strengthens the utility and demand for ETH, solidifying its position as the primary economic asset of the decentralized web.
- Strengthening Decentralization and Resilience: A diverse L2 ecosystem, all relying on L1’s security, further decentralizes the overall network’s functionality. This distributed architecture enhances resilience against potential attacks or failures in any single component.
- Innovation Hub: L2s serve as vital testing grounds for new technologies, applications, and economic models. Successful innovations can eventually inspire or be integrated into L1 upgrades, fostering continuous evolution of the entire ecosystem.
These benefits are not merely theoretical; they represent a long-term thesis requiring continuous validation through real-world experimentation, rigorous measurement, and in-depth analysis. The first five years of the L1-L2 relationship have already yielded significant successes, establishing crucial building blocks for future growth.
Implications for L2s Moving Forward
This updated vision carries tangible implications and recommendations for L2 teams and their communities:
- Embrace Deeper L1 Integration: L2s are encouraged to enhance their integration with Ethereum L1, particularly by striving towards Stage 2 rollup status where applicable. This means increasing their reliance on L1 for security guarantees, fraud/validity proof verification, and decentralized sequencer networks, rather than operating with independent or semi-centralized components.
- Prioritize Shared Security and Interoperability: A key recommendation is for L2s to prioritize architectural decisions that maximize shared security with L1 and foster seamless interoperability with other L2s. This includes adopting common standards for bridging, message passing, and data formats to prevent ecosystem fragmentation.
- Innovate on the Application Layer: With the foundational security and data layers provided by L1, L2 teams are encouraged to focus their innovation on specialized execution environments, novel application designs, and superior user experiences that leverage their unique properties.
- Contribute to the Broader Ecosystem: L2 projects are urged to actively participate in L1 development discussions, contribute to open-source tooling, and engage with the wider Ethereum community. This collaborative approach ensures that L1 upgrades are informed by L2 needs and vice-versa.
- Transparency and User Education: L2s should maintain transparency about their security models, decentralization stages, and any potential risks. Educating users about the benefits and nuances of L2s is crucial for confident adoption.
The Ethereum Foundation’s Commitment
The Ethereum Foundation (EF) recognizes its critical role in facilitating this cohesive L1-L2 future. Its ongoing efforts include:
- Core Protocol Development: The EF continues to fund and lead research and development on Ethereum L1, focusing on key scaling upgrades like proto-danksharding (EIP-4844) and full danksharding. These upgrades are essential for providing cheaper, more abundant data availability for rollups, thereby reducing L2 operating costs and increasing their throughput.
- Tooling and Infrastructure Support: Investing in the development of robust, open-source tooling, client implementations, and infrastructure components that benefit both L1 and L2s. This includes support for ZK-proof systems, bridging solutions, and common standards.
- Research into L2 Security and Design: Actively conducting and funding research into optimal L2 security models, decentralization strategies, and interoperability protocols to guide the ecosystem towards best practices.
- Community Engagement and Education: Facilitating dialogues, workshops, and educational initiatives to foster understanding, collaboration, and knowledge sharing between L1 and L2 developers, researchers, and users.
- Grants and Funding: Providing financial support to projects and teams working on critical L1-L2 infrastructure, research, and open-source contributions.
In summary, the Ethereum ecosystem is moving towards a future where L1 serves as the secure, decentralized settlement layer, and L2s provide diverse, scalable, and specialized execution environments. This synergistic relationship is poised to deliver a global, permissionless on-chain economy and the most comprehensive platform for all users, reinforcing Ethereum’s leadership in the decentralized web. The journey involves continuous collaboration, innovation, and a shared commitment to the core principles that define Ethereum.
