Flashbots

Flashbots grew out of research showing that Ethereum block producers could profit by strategically reordering, inserting, or censoring transactions before confirmation, a practice broadly known as Maximal Extractable Value (MEV). Rather than let this activity stay hidden inside a handful of privileged operators, Flashbots built open infrastructure to surface it and distribute the value more fairly across the network.

Its best-known contribution is MEV-Boost, software that the large majority of Ethereum validators now run to source blocks from a competitive marketplace of specialized "builders" rather than assembling blocks themselves. Builders compete to construct the most profitable block and bid for the right to have it proposed; the validator simply accepts the highest bid. This arrangement, called proposer-builder separation (PBS), routes MEV revenue back toward validators and stakers instead of leaving it entirely with whoever happens to spot a lucrative transaction first.

Flashbots also operates Flashbots Protect, a private transaction relay that lets wallets bypass the public mempool, shielding ordinary users from front running and sandwich attacks that would otherwise worsen their trade prices. After retiring its more experimental SUAVE chain project, the organization shifted its research toward BuilderNet, a decentralized, privacy-preserving block-building network designed to reduce dependence on any single builder or relay operator.

For everyday users of Ethereum, Flashbots' work is mostly invisible but consequential: it shapes how transactions get ordered and included, how much of MEV's economic value returns to network participants rather than sophisticated extractors, and how resistant block production remains to centralization.