Ethereum founder Vitalik Buterin has unveiled the long-awaited roadmap called Lean Ethereum. This is not just another hard fork — it is the third major iteration of the protocol, comparable in scale to the transition to Proof-of-Stake (The Merge). As part of this initiative, virtually every key part of the network will be replaced.
Lean Ethereum is not a one-time update, but a set of improvements that will be implemented over three to four years. The new development roadmap was published after a meeting of Ethereum researchers in Berlin, which continued April discussions with development teams.
What will change in Ethereum
Key changes will affect all major network components. Transaction verification will shift to recursive STARK proofs, replacing direct re-execution. All elements vulnerable to quantum computing will be replaced with quantum-resistant counterparts.
Special attention is given to privacy. According to Buterin, it has ceased to be a secondary task and has become a primary goal: when designing new components, developers now 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 to client architecture are planned. All of this, according to Buterin, will be done with minimal disruption to existing applications.
The most controversial change and scaling plans
Buterin called the changes to state management the most radical part of the plan. A consensus is forming around one approach: the current state type will be left almost unchanged and will grow moderately. At the same time, new state types 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 the current state type and 100 TB of the 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 the new storage type could reduce fees by more than ten times.
Buterin added that over the next five years, there will be repeated increases in the gas limit, growth in the number of blobs, and reductions in block time. A major gas limit increase is expected with the Glasterdam upgrade. Each scaling step, he said, depends on when it becomes safe to implement.
Expert comment: Lean Ethereum is an ambitious step that could redefine the architecture of the second-largest blockchain. However, the key challenge is balancing innovation with stability for the existing DeFi ecosystem. If the plan is realized, Ethereum could become not only more scalable but also significantly more secure in the post-quantum era.