Improving rustc compilation performance (build times)

Working with LLVM upstream to represent Rust in its development

Organizing and managing the Rust compiler team

Writing MIR optimizations and refactoring the MIR to be more optimizable

Implementing the new MIR-based borrow checker and non-lexical lifetimes in Rust

Making parallel compilation the default for rustc

Implementing profile-guided optimization for rustc

Working on an experimental new borrow-checker implementation

Triaging bugs, mainly deciding if bugs are critical (potential release blockers) or not

Improving the behavior of closure-capture, and improving the documentation on closures

Experimenting with a new compiler architecture tailored for IDEs

Make the compiler easier to learn by ensuring that rustc-dev-guide is "complete"

Improving the -Z self-profile feature of the Rust compiler

Revamping the rustc trait implementation to follow the Chalk approach