“Flashbots’ BuilderNet Launches to Break Ethereum’s Centralization and Kill Censorship!”

BuilderNet: Flashbots’ Solution to Ethereum’s Block Building Bottleneck

The Ethereum network is on the cusp of a major transformation. In recent weeks, nearly 88% of Ethereum’s blocks have been built by just two block builders—Beaverbuild and Titan Builder. This alarming centralization of power has exposed the network to risks of censorship and inefficiency. Enter BuilderNet, a decentralized block-building network launched by Flashbots, which aims to disrupt this status quo and fortify Ethereum’s decentralization.

Tackling Centralization in Ethereum

Ethereum’s block-building process relies on the Proposer-Builder Separation (PBS) model, where block builders create blocks for validators (proposers) to review. While this specialization improves efficiency, it has led to the concentration of power among a few players, such as Beaverbuild and Titan Builder.

According to Vitalik Buterin, Ethereum’s co-founder, this centralization creates systemic chokepoints, increasing risks of censorship and rent extraction. For instance, over the past five months, nearly 45% of Ethereum blocks have enforced compliance with U.S. sanctions, data from MEV Watch reveals.

This exclusivity also enables block builders to profit from users through techniques like sandwich attacks, where transactions are manipulated for monetary gain. Titan Builder alone has reportedly earned over $40 million in hidden profits from MEV-Boost, exacerbating the issue.

Enter BuilderNet: A Decentralized Block-Building Network

Flashbots’ BuilderNet, launched on November 26, seeks to “kill censorship” by decentralizing block-building. It runs on a multioperator system, where multiple parties contribute to block creation within a Trusted Execution Environment (TEE).

How BuilderNet Works

BuilderNet introduces a collaborative approach to block-building:

1. Decentralized Collaboration: By distributing the block-building process across many participants, BuilderNet eliminates reliance on a few dominant players.

2. User-Centric Value Redistribution: Maximal Extractable Value (MEV)—the profits extracted by block builders through transaction reordering—is redistributed back to users. Builders are compensated through a refund rule.

3. Layer 2 Integration: BuilderNet is designed as a “drop-in solution” for decentralized sequencing on Ethereum’s Layer 2 networks, further strengthening its utility.

The first iteration of BuilderNet is already live on Ethereum’s mainnet and involves participants like Flashbots, Beaverbuild, and Nethermind. Future versions aim to become fully permissionless, reinforcing resistance to censorship and centralization.

Implications for Ethereum and Block Builders

BuilderNet’s launch signals a pivotal shift in Ethereum’s ecosystem. By decentralizing block-building, it directly challenges the dominance of entities like Titan Builder, whose profitability hinges on centralized MEV extraction. This could lead to a fairer, more resilient Ethereum network.

Coinbase’s protocol specialist, Viktor Bunin, hailed the launch as “absolutely massive,” emphasizing its potential to dismantle exclusive order flow deals that stifle competition.

A Step Toward Ethereum’s Decentralized Future

BuilderNet isn’t Flashbots’ first foray into decentralizing block-building. The firm had previously proposed SUAVE (Single Unifying Auctions for Value Expression) in 2022 but never fully rolled it out. BuilderNet, however, marks a decisive leap toward achieving the network’s decentralization goals.

Flashbots’ commitment to resolving Ethereum’s block-building chokepoints reflects a broader vision: ensuring the network remains secure, equitable, and censorship-resistant. As BuilderNet evolves, it could redefine how block-building operates across decentralized ecosystems.

With BuilderNet’s decentralized approach gaining traction, Ethereum appears poised to overcome its centralization challenges—ushering in a new era of trustless and censorship-resistant blockchain infrastructure.