Proposer-Builder Separation (PBS) is a design pattern that decouples block proposing from block building to improve decentralization, fairness, and MEV extraction transparency. Originally deployed in Ethereum via MEV-Boost, PBS enables specialized builders to create optimized blocks, which proposers select without needing to analyze transaction order. While PBS reduces validator burden and risk of centralization, it introduces new challenges like censorship and trust in relays. Efforts are ongoing to develop in-protocol PBS for native enforcement and broader security. As MEV becomes more widespread, PBS is likely to be adopted across multiple blockchain ecosystems.
Q1: What does Proposer-Builder Separation (PBS) aim to achieve?
A1: Separate block proposal and transaction selection
Q2: Which of the following is a risk introduced by PBS?
A2: Censorship by builders or relays
Q3: What is a potential benefit of in-protocol PBS over MEV-Boost?
A3: Native enforcement of rules
Q4: Who competes to build the most profitable blocks in PBS?
A4: Builders
