Definition ∞ PBS architecture, or Proposer-Builder Separation architecture, is a design modification for blockchain consensus mechanisms that divides the role of block production into two distinct parts. A “builder” assembles transactions into a block, potentially optimizing for Maximal Extractable Value (MEV), while a “proposer” then selects and proposes a block from available builders. This separation aims to mitigate centralization risks and improve network fairness. It is a significant structural change in how blocks are created and validated.
Context ∞ PBS architecture is a highly discussed topic, particularly in the context of Ethereum’s post-merge roadmap, aiming to address MEV-related centralization concerns. Debates involve the optimal design of the builder-proposer interface and the potential for new forms of collusion or censorship. Future developments include the iterative implementation and refinement of PBS in major blockchain protocols, seeking to balance efficiency, decentralization, and resistance to censorship.