Karl Floersch is a Co-Founder of Optimism and serves as Chief Technology Officer of OP Labs. He has been a prominent voice in the Ethereum scaling and public-goods funding communities, combining protocol engineering with advocacy for sustainable ecosystem development.
Floersch was an early Ethereum researcher and contributor before co-founding Optimism. He played a key role in the transition from Plasma Group — an earlier Ethereum scaling research organization — to the optimistic rollup model that became Optimism. His work on the OP Stack architecture has made it one of the most widely adopted open-source Layer-2 frameworks, powering not only Optimism but also chains like Base and Worldchain.
As CTO, Floersch leads the technical direction of OP Labs, focusing on protocol security, the superchain architecture and cross-chain interoperability. He is also known for his advocacy of retroactive public-goods funding as a model for sustaining open-source development in the Ethereum ecosystem. Information last checked: August 2026.
