zlib × Lean Languages: EN / ZH Follow the data through the algorithm, then the implementation through the proof. Inside the V8 Sandbox Notes on V8's sandbox threat model, attack boundary, and the browser code that still has to treat sandbox data carefully. Learning Lean as a Programmer Learning Lean from the perspective of a programmer: types as propositions, proofs as programs, and raw induction machinery. Bitcoin From the Top Down Languages: EN / ZH A top-down walkthrough of Bitcoin's data model, from peer-to-peer state to transactions, UTXOs, and script validation.