Taiko COO on What Fusaka Really Means for Ethereum

Ethereum’s Fusaka upgradewent live on December 3, reducing Layer 2 data costs, increasing network capacity, and strengthening the network’s core infrastructure. On top of this, Taiko COO Joaquin Mendes noted in a recent comment to BSCN that the upgrade also signals a shift in how Ethereum expects rollups to operate, especially those built around L1 sequencing such as Taiko.

Fusaka improves Ethereum’s data availability model, introduces deterministic proposer lookahead through EIP-7917, adjusts block parameters, and prepares the network for future rollup-heavy activity. For Taiko and other L1-sequenced rollups, these changes are substantial, practical, and highly technical. They affect how data flows, how validators coordinate, and how rollups confirm transactions.

What Is Fusaka and Why Does It Matter?

Ethereum relies on rollups for most transaction activity. When those rollups get expensive or congested, the entire ecosystem slows. Fusaka addresses this by improving how Ethereum handles data posted by rollups.

Fusaka’s main goals are as follows:

• Increase the amount of Layer 2 data Ethereum can safely handle
• Reduce blob costs so rollups become cheaper
• Improve validator efficiency
• Strengthen spam resistance
• Prepare Ethereum for the long-term Danksharding roadmap

This upgrade follows earlier steps in Ethereum’s evolution. The Merge introduced proof-of-stake. Pectra improved wallet functionality and validation rules. Fusaka now focuses on scaling Ethereum’s data layer, which is the foundation for rollups like Taiko.

From Taiko’s viewpoint, the most important elements are data availability improvements and deterministic proposer lookahead. Both directly affect how L1-sequenced rollups operate.

How Does Fusaka Change Ethereum’s Data Model?

Before going into Taiko’s interpretation, it is important to understand PeerDAS, the central feature of Fusaka.

Introduction

PeerDAS stands for Peer Data Availability Sampling. It changes how Ethereum verifies the large “blob” data that rollups publish.

Before Fusaka

Every validator needed to download entire blobs. This worked when rollups produced less data, but it became a burden for home stakers with average internet connections.

After Fusaka

Validators only verify small pieces of the data. Through erasure coding, Ethereum can still reconstruct the full data set even if each validator sees only a small slice.

What PeerDAS Achieves

• Up to eight times more throughput for rollup data
• Around 85 percent lower bandwidth use for validators
• More decentralization since home stakers face smaller hardware requirements
• Faster settlement for rollup transactions

The logic is similar to checking random pages of a book instead of reading the entire book. If enough people check different pages, everyone knows the full book is intact.

This is a key part of Ethereum’s long-term plan. It makes large rollup ecosystems sustainable without turning Ethereum into a system that requires data center-grade hardware.

Is Fusaka Changing Ethereum’s Role?

Mendes says yes, in a practical sense. Ethereum is no longer trying to handle all execution, computation, and settlement. Instead, it is positioning itself as a secure base layer for data availability and consensus.

From Taiko COO Joaquin Mendes:

“L1 isn’t trying to do everything for everyone anymore. It’s becoming infrastructure for data availability and consensus coordination, assuming rollups will handle execution.”

This reflects the reality of today’s ecosystem. The highest-volume activity already happens on rollups. Fusaka reinforces this model by making it cheaper for rollups to post data and easier for validators to keep up.

But it also introduces new expectations. Rollups now require reliable blob access. Mendes notes that this means running beacon clients in semi-supernode or supernode configurations. It is a tradeoff: more throughput, but heavier requirements for rollup operators who rely heavily on blobs.

Taiko accepts this cost because the benefits to its architecture are significant.

What Does EIP-7917 Do and Why Does It Matter for Taiko?

One of the most important elements of Fusaka is EIP-7917. It introduces deterministic proposer lookahead. This means Ethereum’s Beacon Chain now knows the upcoming block proposers for the next epoch.

Why this matters

Rollups can now coordinate with future block proposers instead of waiting for blocks to be included. This enables preconfirmation mechanisms, which let a rollup commit to transaction inclusion before the actual block lands on-chain.

Taiko COO Joaquin Mendes explains:

“Rollups can now commit to transaction inclusion with upcoming validators instead of waiting for blocks to land. For based rollups specifically, this matters.”

A “based rollup” is one that uses Ethereum’s L1 as the sequencer. Taiko follows this model. Because Taiko depends on L1 sequencing, having visibility into who will propose blocks gives it design advantages that other rollups cannot easily replicate.

Practical benefits for Taiko

• Preconfirmations become possible
• Sequencing latency becomes more predictable
• The rollup can align its architecture with Ethereum’s timing
• Risk of reorg-related delays becomes easier to manage

This is a significant structural advantage for any rollup built around L1 sequencing.

Fusaka’s Phased Rollout and What It Signals

Fusaka is not a single event. It is a phased upgrade:

• December 3: Fusaka activation
• December 9: Blob Parameter Only fork
• January 7: Second Blob Parameter Only fork

These smaller “parameter-only” forks allow Ethereum to increase blob capacity without performing a full hard fork. The network can now adjust to demand more frequently and with less complexity.

Mendes highlights this as a change in how Ethereum evolves:

“Ethereum can now iterate on DA capacity as demand requires rather than waiting for major upgrades.”

This means rollups can plan with more clarity. For Taiko, it means a predictable scale-up path that fits its model of L1 sequencing.

Does Fusaka Affect Block Capacity and Fee Stability?

Fusaka increases the effective block gas limit from around 36 million to about 60 million. It also introduces new rules about blob pricing and block size.

Key changes include:

• EIP-7918: Adjusts blob fee pricing
• EIP-7934: Prevents oversized blocks
• EIP-7825: Introduces transaction gas limits inside blocks

Why these changes matter

• Rollups get more predictable posting slots
• Layer 2 fees stabilize
• Congestion spikes become less severe
• Ethereum becomes more reliable during high-volume periods

These mechanics support the goal of making Ethereum a strong data availability layer rather than a general-purpose settlement bottleneck.

How Fusaka Improves Daily User Experience

Most users will not need to take any direct action. But the effects appear across the ecosystem:

• Lower rollup fees
• Fewer failed transactions during busy market moments
• More stable DeFi execution
• More responsive applications

Biometrics and secp256r1

Fusaka adds support for the secp256r1 signature scheme. This makes it possible for smartphones to sign transactions using built-in hardware security features. In the future, users might approve transactions through Face ID or a fingerprint sensor rather than typing seed phrases.

This does not replace existing wallets, but it expands the design choices for wallet developers.

Conclusion

Fusaka improves Ethereum’s data availability, reduces rollup costs, strengthens validation, expands block capacity, and enables deterministic proposer lookahead. These changes benefit the entire ecosystem, but they offer special advantages to L1-sequenced rollups like Taiko. The upgrade gives Ethereum a more efficient foundation and gives Taiko a clearer architectural roadmap. Fusaka focuses on capability increases rather than speculation, and its effects are already shaping how rollups prepare for the next stage of Ethereum’s scaling plan.

For Taiko, Fusaka expands the advantages of L1 sequencing. Deterministic proposer lookahead, greater blob capacity, and more predictable data availability allow Taiko to refine its architecture in ways that other rollup models cannot easily copy.

Resources

1. Ethereum on X: Announcement (Dec. 3)

2. Consensys Fusaka dashboard: About Fusaka upgrade

3. Report by Blockworks: Ethereum’s Fusaka upgrade lands today

4. Taiko docs: About Taiko