Worked on the facebook/pyrefly repository to address reliability and developer experience by fixing a critical bug in static analysis related to walrus operator usage within comprehension filters. The solution involved implementing enclosing-scope flow checks in Rust, which eliminated false uninitialized variable errors and improved analysis accuracy. To ensure stability, targeted tests were added to cover walrus-in-comprehension scenarios, strengthening regression safety. Additionally, documentation for the infer-return-types option was enhanced using Markdown, with clearer headings, cross-references, and practical examples to improve discoverability. All changes were validated through formatting and linting checks, maintaining code quality and coherence across the project.