Yeah, I was actually recommended the instrumentation route by a commenter on Reddit.

I spent a similar amount of time setting up opentelemetry with Next and while it would have been titled differently, I would have likely still written a blog post after this experience too.

This isn't your fault, but basically every opentelemetry package I had to setup is marked as experimental. This does not build confidence when pushing stuff to production.

Then, for the longest time I couldn't get the pino instrumentation working. I managed to figure it out eventually, but it was a pain.

First, pino has to be added to serverExternalPackages. If it's not, the OTel instrumentation does not work.

Second, the automatic instrumentation is extremely allergic to import order. And also for whatever reason, only the pino default export is instrumented. Again, this took a while to figure out.

Module local variables don't work how I would expect. I had to use globalThis instead.

And after all that I was still hit by this: https://github.com/vercel/next.js/issues/80445

It does work, but it was not great to set up. Granted, I went with the manual router (eg. not using vercel/otel).