Worked on enhancing Markdown URL autolinking reliability in the markedjs/marked repository by addressing case sensitivity in the detection of the 'www.' prefix. Focused on refining regular expressions to ensure accurate parsing of URLs, particularly across different capitalizations and protocols, which reduced both false positives and negatives in rendered output. Expanded the test suite to cover a broader range of edge cases, improving overall Markdown rendering consistency for downstream consumers. Utilized TypeScript, HTML, and Markdown while emphasizing robust testing and defect-driven collaboration. The work resulted in fewer user-facing link errors and lowered maintenance costs through more resilient parsing logic.