Vitalik Buterin has published an updated development roadmap for Ethereum outlining Lean Ethereum, a multi-year transformation spanning 3 to 4 years that marks the blockchain's third major iteration following The Merge. The overhaul will fundamentally restructure how the protocol verifies blocks, secures transactions, and executes smart contracts.
The roadmap introduces recursive STARK proofs as a native protocol component, replacing full transaction reprocessing for block verification. This technology, developed by StarkWare (creators of Starknet), will be integrated directly into Ethereum's consensus layer. Alongside this, the protocol will adopt post-quantum cryptography across all operations and transition from the Ethereum Virtual Machine (EVM) to RISC-V or leanISA as the base virtual machine. The overhaul will also shift privacy from the application layer to the protocol layer itself, while consensus will be streamlined through separation of availability and finality, reducing block finality to 1–2 rounds.
Fee reductions represent perhaps the most immediate user-facing benefit, with new state types enabling a 10x or greater decrease in transaction costs for ERC-20 tokens, NFTs, and most DeFi applications. The upcoming Glamsterdam upgrade in the second half of 2026 will serve as the first major step, increasing the gas limit from the current approximately 60 million to 200 million, with Ethereum expected to significantly expand throughput multiple times over the next five years.
While Starknet itself does not directly participate in Lean Ethereum's development, the adoption of its proven STARK technology represents a significant validation of recursive proof systems for mainstream blockchain infrastructure.