Keith Chi Kit Y.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

Senior Rust engineer with 10+ years of production experience, currently focused on blockchain protocol infrastructure. I led the implementation team for XCM at Parity Technologies from 2021 to 2024, served as lead reviewer on protocol-level changes, authored security-driven and invariant-level work, and shepherded community RFCs through the polkadot-fellows process. XCM, designed by Gavin Wood, is Polkadot's cross-chain messaging protocol now in use across 50+ parachains, with 200+ active channels and peak throughput of 130K+ messages per quarter. Most recently I was at Polygon Labs working on the AggLayer cross-chain ZK proof aggregation system, where I shipped Rust performance optimizations including compile-time Merkle tree pre-hashing. Earlier in my career I rewrote a proprietary DSL compiler in Rust for a 5x runtime speedup at F5 / Shape Security and optimized user-agent string parsing by 73x. What I can help with: * Protocol design and architecture (cross-chain messaging, consensus, runtime modules) * Substrate and Polkadot ecosystem engineering (FRAME pallets, XCM integration, parachain runtimes) * Rust performance optimization (profiling, async patterns, compile-time evaluation, zero-cost abstractions) * Smart contract development on EVM chains (Solidity, with prior code-bounty experience) * Code review and technical mentorship for Rust codebases * Migrations from other languages to Rust Open source contributions: * Rust compiler (rust-lang/rust): contributing member of the NLL working group, MIR borrow checker, diagnostics * Servo browser engine: EventSource, CORS preflight fetch, fetch infrastructure * Substrate (paritytech): StorageNMap support, ResultQuery, construct_runtime! macro improvements * WHATWG specifications: Fetch, HTML, and XHR (three and a half years contributing voluntarily at Mozilla Research) Teaching and speaking: * Invited XCM instructor at the Polkadot Blockchain Academy across three cohorts (Cambridge, Buenos Aires, Hong Kong) * Speaker, "The Future of XCM" at Polkadot Decoded 2023 Education: B.A.Sc. in Computer Engineering, University of Waterloo. Working languages: English, Cantonese, and Mandarin (native), Japanese (JLPT N2 certified, business-level proficiency), and intermediate French.