Block Builder

Definition ∞ A block builder is an entity responsible for collecting and ordering transactions into a block on a blockchain network. This role is particularly prominent in proof-of-stake systems, where builders optimize transaction inclusion to maximize value, often through strategies like MEV (Maximal Extractable Value). Block builders propose these constructed blocks to validators for inclusion in the chain. Their activity directly influences transaction processing efficiency and network economics.
Context ∞ The role of block builders has become a significant area of focus in blockchain development, especially concerning decentralization and fairness. Debates continue regarding the potential for centralization of block production and the implications of MEV extraction on network integrity. Future protocol upgrades and regulatory considerations frequently address mechanisms to distribute block building power and mitigate potential abuses, aiming for more equitable transaction ordering.