Builder network and MEV-Boost
Consensus clients are responsible for proposing blocks containing an execution payload obtained from their local execution clients via the Engine API.
A consensus client can optionally configure an external builder and delegate the execution payload construction to it, instead of using the execution client.
The most common builder deployment is to run a specialized external software such as MEV-Boost. MEV-Boost works by requesting a payload proposal from several entities (called relays), and selecting the best bid in order to improve validator rewards and increase the maximal extractable value (MEV).
Teku allows you to configure the beacon node to use a builder network to generate execution payloads. In case of failures or non-timely responses, Teku falls back to the payload produced by the local execution client specified using