Worked on the sveltejs/kit repository to address asset delivery reliability by fixing a caching issue affecting immutable assets. Focused on backend development and caching strategies using JavaScript, the work involved modifying HTTP cache-control headers to prevent 404 responses for missing assets from being cached. This change ensured that when assets were reintroduced after a deployment, clients would not continue to receive stale 404 errors. The solution was validated both locally and in preview deployments, resulting in improved cache hygiene and a more robust user experience by reducing persistent missing asset errors after updates to the application’s deployment environment.