Barnabé Monnot

In the past months, I’ve harped on Proposer-Builder Separation, and the Principal-Agent Problem more generally. One reason is the depth of research questions, bringing in the mix considerations from both the consensus layer and the execution layer, plus everything in-between, such as MEV, the transaction supply network, and the growing web of out-of-protocol markets and institutions.

Before we get started: Dear e-mail subscriber, due to the length of this post, it is possibly truncated by your e-mail client! If things end abruptly, take a look at the post online by clicking on the title. Thank you for reading :) Proposer-Builder Separation (PBS) is a hotly debated topic, a broad design philosophy emphasising the relationship between protocol and non-protocol actors for the maintenance and operation of a blockchain.

On May 25th 2022, at 08:55 UTC, a 7 block re-org occurred on the beacon chain. We aim here to provide a visual guide to understand the Ethereum Proof-of-Stake protocol and why the re-org happened. In a nutshell, the re-org is not expected behaviour of the beacon chain. It occurred due to an unhappy combination of three distinct causes: A late block proposal split views of validators due to a recent fork choice update called proposer boost.