Vitalik Buterin announced Lean Ethereum: the third era of the network, comparable in scale to The Merge
Ethereum founder Vitalik Buterin has unveiled an updated network development roadmap called Lean Ethereum. In his assessment, this is the third major iteration of the protocol, comparable in significance to the transition to Proof-of-Stake (The Merge). This update will replace nearly every key part of the network.
Buterin explained that Lean Ethereum is not a one-time update, but a set of improvements that will roll out over three to four years. The new roadmap was published after a meeting of Ethereum researchers in Berlin, continuing April discussions with development teams.
What will change in Ethereum
Changes will affect almost all core components of the network. Transaction verification will shift to recursive STARK proofs instead of direct re-execution. All elements vulnerable to quantum computing will be replaced with quantum-resistant counterparts.
Buterin specifically highlighted the priority of privacy. According to him, it has ceased to be a secondary task and has become a primary goal: when designing new components, developers directly ask how private transactions pass through them without intermediaries.
Buterin also emphasized the increased priority of quantum security. This adds a lot of work—for example, finalizing a quantum-resistant design for blobs has become urgent, a task the team has been working on for several months.
Additionally, formal verification of all components for security, a multidimensional gas fee model, and changes in client architecture are planned. According to Buterin, all of this will be done with minimal disruption to existing applications.
The most controversial change and scaling plans
Buterin called changes to state management the most radical part of the plan. Consensus is forming around one approach: the current type of state will be left almost unchanged and will grow moderately. In parallel, new types of state will be added—they scale much better but are not suitable for all tasks.
As an example, the Ethereum founder cited a possible network configuration by 2030: 2 TB of current state type and 100 TB of new state type. The new format will be well-suited for ERC20 tokens, NFTs, and many DeFi scenarios, but not for complex "central" objects like Uniswap contracts or on-chain order books.
According to Buterin, rewriting applications is not mandatory, but it will be very beneficial. For instance, moving an ERC20 token to a new storage type could reduce fees by more than ten times.
Buterin added that over the next five years, there will be multiple increases in the gas limit, growth in the number of blobs, and a reduction in block time. A major gas limit increase is expected with the Glasterdam update. Each scaling step, he said, depends on when it becomes safe to implement.
My expert assessment: Lean Ethereum is not just another hard fork, but a fundamental architectural overhaul. If The Merge solved the energy consumption problem, the new roadmap aims to eliminate key bottlenecks: scalability, privacy, and quantum resistance. Particularly interesting is the approach of preserving legacy state while parallelly introducing new storage types—a pragmatic compromise that will not break the existing ecosystem but will provide a strong incentive for applications to migrate to more efficient rails. If the plan is implemented, Ethereum by 2030 could become a completely different network.