Vitalik Buterin maps ‘Lean Ethereum’ as the network’s third major overhaul

Vitalik Buterin has published an updated long-term roadmap for Ethereum, calling the multi-year effort “Lean Ethereum” as the network’s biggest redesign since the Merge. He posted it to X on July 4, 2026, days after Ethereum researchers gathered in Berlin to work on the protocol’s long-term trajectory.     

Buterin’s post is important to those building on Ethereum, which consists of developers, layer-2 networks that settle on it, and the ETH holders who are observing how well the blockchain continues to run without breaking what is already running on top of it. 

The Ethereum co-founder says that every core component will be rebuilt, but slowly, over the next three to four years.

According to Buterin’s post, the revised plan now lives in Ethereum’s public strawmap.

Ethereum to go through a phased rebuild

Buterin stated that his key takeaways from that event is that “Lean Ethereum” is not a single one-shot upgrade.

He added that “it is a collection of improvements that will come online to the Ethereum network over the course of three or four years.” 

However, he also pointed out that this will be the third major iteration of Ethereum, comparing it to the Merge, which is the second major iteration when the network moved from a proof-of-work (PoW) consensus mechanism to a proof-of-stake (PoS) system. 

Buterin wrote that “almost every major piece of the protocol will be replaced.”

The technical scope is wide, as the roadmap proposes swapping direct transaction re-execution for recursive STARK-based verification. Buterin also pointed out that they are replacing everything that is quantum-vulnerable with alternatives that are quantum-safe, adding that it is a major priority.  

He also added that they will be reworking consensus toward one- or two-round finality, introducing multidimensional gas pricing, moving to new state architectures, and making changes to client architecture. 

Buterin stated that the changes can be done in a way that minimizes disruption to the existing application, pointing to the Merge as evidence that Ethereum can execute large upgrades. The cofounder stated, “We’ve done this before (the Merge), we can do it again.”

What is the Ethereum Foundation doing about privacy and quantum defense?

Buterin said future protocol design will treat privacy as built in. “Privacy is no longer an afterthought; it is a first-class goal,” he wrote. 

He added that developers are now asking questions that touch on how well intermediary-free, quantum-safe privacy is supported without heavy overhead when designing new components such as Frames, the mempool, and additions to the state tree.

Quantum resistance has climbed the list too. Buterin said work on quantum-safe blob designs has already run for several months.

A state model built for 2030

The most far-reaching idea concerns how Ethereum stores data. Buterin stated that “there is growing consensus around leaving present-day-style ‘dynamic state’ mostly unchanged, but scaling it only a medium amount.”

He added that consensus also supports adding new types of state that are easier to scale at large, but also relatively more restrictive.

Buterin gave an example stating that it is possible that Ethereum in 2030 will be holding about 2 TB of present-day-style (dynamic) state alongside 100 TB of a newer, more scalable design suited to ERC-20 tokens, NFTs, and many DeFi uses, while decentralized exchanges and on-chain order books stay on the existing model. 

Migration would be optional but financially attractive, not mandatory.

Buterin also floated moving past the Ethereum Virtual Machine (EVM) entirely, toward an execution environment such as RISC-V or leanISA, with the EVM eventually acting as a compiler target rather than the engine itself.

Is Ethereum trying to build a leaner protocol as its Foundation slims down?

The roadmap lands during a turbulent stretch for Ethereum’s institutions. Buterin stated in a June post that the Ethereum Foundation is cutting its budget by about 40% this year. It shed 54 jobs, roughly 20% of staff, on June 22. Also, several departed researchers have regrouped at Ethlabs, a new nonprofit that says it can fund operations for two to three years.

The ETH market has also taken a hit in recent times, although it is not unique to it alone, as funds are reportedly moving from crypto into AI investments. ETH currently trades around $1,760, down over 64% from its August 2025 high of $4,953.73.