Anything related to observability with Next.js is guaranteed to be a fucking nightmare. At work we'll typically implement a metrics endpoint for Prometheus - really trivial for just about every API or fullstack framework under the sun, except Next.js. I think I gave up at the point where the suggested method was using a custom server (negating some of Next.js's supposed benefits), or adopting Vercel's proprietary metrics service which wouldn't have helped us anyway. Terrible, terrible stuff - would never touch again.