Developed cross-repository threading shims to expand concurrency support in no_std environments, focusing on the rust-lang/miri and rust-lang/rust repositories. Leveraging Rust and advanced concurrency techniques, introduced Miri-specific thread management shims that enable thread spawning and joining without relying on the standard library. This work established consistent threading interfaces across both repositories, reducing integration risks and supporting interpreter-level concurrency. The implementation improved portability and enabled embedded testing capabilities, broadening the applicability of no_std code paths. By coordinating updates across core Rust components, the developer enhanced support for concurrent workloads in embedded systems, tooling, and interpreter-based environments using no_std Rust.