Ethereum founder Vitalik Buterin has officially introduced the concept of "Lean Ethereum" — the third major iteration of the protocol, which he places on par with the historic transition to Proof-of-Stake (The Merge). This is not a one-time upgrade, but a strategic set of improvements that will be implemented over the next three to four years.
The new roadmap was shaped following a closed meeting of Ethereum researchers in Berlin, which continued discussions from April with developer teams. As part of "Lean Ethereum," it is planned to replace virtually every key component of the network.
What will change in Ethereum
According to published data, the changes will affect all fundamental levels. Transaction verification will transition to recursive STARK proofs, completely replacing direct re-execution. All elements vulnerable to quantum computing will be replaced with quantum-resistant alternatives.
Buterin paid special attention to privacy. According to him, it has ceased to be a secondary task and has become a first-order priority: now, when designing new components, developers directly ask how private transactions will pass through them without intermediaries.
The relevance of quantum security has also increased. The team has been working for several months on finalizing a quantum-resistant design for blobs. Additionally, the plan includes formal verification of all components, a multidimensional gas fee model, and changes in client architecture. Buterin emphasizes that all of this will be implemented with minimal disruption to existing applications.
The most controversial change and scaling plans
Buterin called the changes in working with the network state the most radical part of the plan. Consensus is currently forming around one approach: the current state type will be left almost unchanged and will grow moderately, while a new state type will be added in parallel, which scales much better but is not suitable for all tasks.
As an example, Buterin 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.
Rewriting applications is not mandatory, but it will be very beneficial. For example, moving an ERC20 token to the new storage type could reduce fees by more than ten times.
Buterin also confirmed that over the next five years, there will be repeated 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 upgrade. Each scaling step, he says, depends on when it becomes safe to implement.
Cryptalist analytical commentary: "Lean Ethereum" is not just an upgrade, but a fundamental restructuring of the architecture that lays the foundation for the next decade. The focus on privacy and quantum resilience deserves special attention: it is a signal to the market that Ethereum is preparing for challenges that most projects are currently ignoring. If the plan is implemented, we will see not only an increase in throughput but also a qualitative change in the network's security model.