# Vitalik Buterin Unveils leanVM: A New Step in Ethereum Scaling

Ethereum co-founder Vitalik Buterin has announced leanVM, a proposal aimed at advancing Ethereum’s scalability, decentralization, and sustainability. He noted that 2025 has already brought significant progress toward the network’s short-term scaling roadmap, with key milestones now approaching.

What is leanVM? 🔑

A minimal zkVM (zero-knowledge virtual machine) designed to enhance efficiency.

Optimized for XMSS aggregation and recursion.

Uses a four-instruction architecture (ISA), multi-linear STARKs, and the logup-lookup cryptographic technique, cutting commitment costs compared to Cairo.

Current recursion speed is 2.7 seconds, with the team targeting a 10x improvement.

Buterin praised the Ethereum lean team’s efforts:

> “They have made progress on all fronts this year. I expect these ideas to materialize alongside the next key milestones in our short-term scaling roadmap.”

On Protocol Design 🎨
Vitalik stressed the importance of simplicity:

> “Protocols are not something hastily written with garbage for short-term convenience. They are a work of art, and should look accordingly.”

Roadmap Synchronization 🗓️
He explained that the lean roadmap is intentionally designed to lag behind short-term scaling phases, ensuring readiness exactly when those upgrades are fully live on mainnet. This ZK-friendly approach allows Ethereum to scale safely and efficiently without heavy infrastructure demands.

Recent & Upcoming Milestones

May 7, 2025: Ethereum successfully completed the Pectra update on mainnet.

November 2025: Developers plan to release the next major upgrade, Fusaka.

With leanVM and the upcoming Fusaka release, Ethereum continues to strengthen its position as a scalable, sustainable, and secure global blockchain. 🌐🔥