What to expect from Ethereum's Fusaka upgrade

Ethereum developers are highly optimistic about Fusaka, a major upgrade designed to improve how the Ethereum mainnet collects and verifies data from layer-2 networks, which will be completed on December 3. The main goal of Fusaka is to make rollups—a layer-2 scaling solution—cheaper, faster, and more scalable.

What are Layer-2 and rollups?

Layer-2 are scaling networks that operate “on top of” Ethereum, helping to process more transactions without clogging the mainnet. Rollups are one of the most popular layer-2 mechanisms, bundling multiple transactions together and sending aggregated data back to Ethereum for verification, reducing fees and increasing speed. Fusaka aims to optimize how the mainnet handles data from these rollups.

Nick Johnson, co-founder and lead developer of Ethereum Name Service (ENS), said:

“This directly supports the ecosystem that the majority of users interact with daily.”

He also emphasized that the upgrade demonstrates the maturity of Ethereum: instead of focusing on major new features, upgrades are now about efficiency, decentralization, and resilience. Fusaka strengthens Ethereum’s (base layer) enough to support long-term growth without losing the core attributes that make Ethereum trustworthy.

What is Fusaka?

Fusaka stands for Fulu-Osaka, following the Pectra upgrade in May, which introduced smart contract functionality for wallets, improved validator mechanisms, and enhanced network scalability.

This Fusaka upgrade will boost scalability by increasing blob capacity in each transaction block through the PeerDAS proposal (EIP-7594).

What are blobs and PeerDAS?

• Blobs are a type of temporary data that store information from layer-2 networks, reducing gas fees and not taking up long-term space on the blockchain. Blobs were first introduced in the Dencun 2024 upgrade.
• PeerDAS (Proposer/Peer Data Availability Sampling) is an improved mechanism that replaces the old “store all data” approach with sampling. Instead of every node retaining all the data, PeerDAS allows for data availability checks by sampling, reducing costs and increasing processing speed.

Ansgar Dietrichs from the Ethereum Foundation explained:

“PeerDAS is really the foundation of this fork. Essentially, it changes the way we do state confirmations, from a simple data mechanism to a sampling-based one.”

With Fusaka, blob capacity is expected to increase eightfold, enabling rollups to operate more smoothly and making the Ethereum network viable for large-scale applications.

Alon Muroch, co-founder of staking company SSV Labs, stated:

“Fusaka is an important step toward a highly interoperable Ethereum, allowing rollups to function as a unified ecosystem under Ethereum’s security. This brings the network closer to its original vision: a ‘decentralized world computer,’ but with a unified ecosystem.”

Vitalik Buterin’s perspective

Ethereum co-founder Vitalik Buterin called the features unlocked by PeerDAS “unprecedented” and emphasized that this is the key to scaling layer-2, and ultimately layer-1. Layer-1 is Ethereum’s base layer, where all transactions are finalized. This means PeerDAS not only helps layer-2 but also lays the foundation for scaling Ethereum itself directly.

The next upgrade: Glamsterdam (2026)

Ethereum is developing its next major upgrade, Glamsterdam, expected to launch in 2026, focusing on expanding layer-1 and blob capacity, further improving network performance.

ETH rose nearly 10% on Tuesday, trading around $3,000. Over the past 7 days, ETH’s price has increased by about 4.3%, but it remains nearly 39% below its all-time high of $4,946 in August. Nevertheless, forecasters on Myriad believe ETH could fall to $2,500 before breaking out to $4,000.

Thach Sanh