Hasu and Jon bring on Mike Neuder (Ethereum Foundation) and Chris Hager (Flashbots) to discuss the design philosophy of proposer-builder separation (PBS). They first dive into the past and present implementations of PBS, including MEV-Geth and MEV-Boost on Ethereum. Then they discuss the future of PBS - whether PBS should be enshrined, protocol-enforced proposer commitments (PEPC), PBS on L2s, how to prevent censorship, and more.

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Timestamps:

(00:00) Intro

(01:12) What is PBS?

(05:37) The History of PBS

(08:43) MEV-Boost

(10:18) Block Production in Proof-of-Work

(11:31) Benefits of PBS

(14:17) PBS Makes Based Rollups Viable

(16:21) PEPC & Proposer Complexity

(17:46) Other Builder Services

(19:49) PBS & Regulation

(22:48) Regulation & Encrypted Mempools

(24:38) Division of Labor is Inevitable

(26:15) Risks of PBS

(29:03) Development of COre Protocol Software

(33:31) PEPC, POB, & Alternatives to PBS

(41:53) Decentralization vs. Usefulness Tradeoff

(46:30) State of PBS in MEV-Boost

(50:51) Optimistic Relays

(52:09) Enshrined PBS (ePBS)

(55:55) PBS on L2

(58:47) PEPC

(01:05:25) Proposer Commitments & User Intents

(01:09:03) Concluding Remarks

(01:11:05) Recap

(01:12:06) PEPC, PEPC-Boost, & MEV-Boost+

(01:18:44) PBS From First Principles

(01:21:41) PBS is a Philosophy, Not an Implementation

(01:25:44) To Enshrine, Or Not to Enshrine?

(01:35:12) In-protocol vs. Out-of-protocol Development & Funding

(01:50:16) Censorship & Proposer Agency

(01:58:15) Outro & Disclaimer

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Hasu - https://twitter.com/hasufl

Jon Charbonneau - https://twitter.com/jon_charb

Uncommon Core 2.0 - https://twitter.com/UCC2_xyz

Mike Neuder - https://twitter.com/mikeneuder

Chris Hager - https://twitter.com/metachris

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Relays in a post-ePBS world - https://ethresear.ch/t/relays-in-a-post-epbs-world/16278

No free lunch – a new inclusion list design - https://ethresear.ch/t/no-free-lunch-a-new-inclusion-list-design/16389

Payload-timeliness committee (PTC) – an ePBS design - https://ethresear.ch/t/payload-timeliness-committee-ptc-an-epbs-design/16054

Notes on Proposer-Builder Separation (PBS) - https://barnabe.substack.com/p/pbs

PEPC FAQ - https://efdn.notion.site/PEPC-FAQ-0787ba2f77e14efba771ff2d903d67e4#41230925420345af84f31b50d806b8ed

PEPC Open Problems - https://docs.google.com/presentation/d/12kpwAXbZqUA0fu2HnZKSesVwO31ICbgIiacHd0EQ_fk/edit#slide=id.g2401d3821ec_1_0

PBS Guild Proposal [v3 WIP] - https://collective.flashbots.net/t/pbs-guild-proposal-v3-wip/2223

MEV-Boost+/++ - https://www.blog.eigenlayer.xyz/censorship-resistance-with-restaking/

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Disclaimer: The material and information presented in this podcast is for general informational purposes only and should not be considered investment advice. The views, thoughts, and opinions expressed in this podcast are solely those of the speakers and are not the views of any entity or other person with whom the speaker is affiliated, including, without limitation, DBA Crypto, LLC. The “DBA Crypto” name and all forms thereof are the sole property of its owner, and its use does not imply endorsement of or opposition to any specific organization, product, or service.

THE WAR ROOM WITH STEPHEN K. BANNON, SEPTEMBER 17TH, 2025, EP.#4786