Worked on enhancing the PostHog/posthog-js repository by implementing client-side compatibility improvements for Next.js integrations. Focused on introducing runtime-aware exports to ensure server-only components were isolated from client builds, this approach reduced server dependency leakage and improved reliability for client applications. Updated the client-facing default export for @posthog/next/pages to mirror the appropriate client version, preventing server-side dependencies from appearing in client bundles. The work included updating tests to validate the new export behavior and documenting the changes in a changeset. Utilized JavaScript, Next.js, and Node.js, establishing a foundation for future host-agnostic packaging and streamlined integration.