Bitcoin developer "Burak", known for exposing a bug in the Lightning Network, is developing a new Bitcoin layer 2 called "Brollups". This layer aims to bring more decentralized finance (DeFi) use cases to Bitcoin without requiring a hard fork or issuing a non-Bitcoin token. Brollups, currently in the design phase, could see a testnet rollout later this year. The layer is expected to support over 90% of DeFi use cases, including NFT sales and token sell orders on decentralized exchanges. Transactions will be executed on the Bitcoin Virtual Machine and managed by "operators" who provide liquidity and advance the rollup state.