Worked on the wpengine/faustjs repository to deliver compatibility with Next.js 15 and React 19 RC, focusing on stabilizing the experimental app router and improving authentication flows. Addressed technical challenges around cookie handling, server actions, and parameter awaiting to ensure smoother migrations for downstream applications. Enhanced the login form by adopting React 19’s useActionState, resulting in more reliable and responsive user interactions. The work was implemented using TypeScript and JavaScript, leveraging skills in Next.js, React, and server actions. These updates laid the groundwork for future feature integrations and reduced upgrade friction for applications depending on Faust.js moving forward.