Lots of good insights in here. Of course YMMV and some definitely depends on your context. That's a lot of dimensions to keep in mind though.

Still very young but it looks like it might become a nice and friendly alternative to strace.

Lots of good advice on how to improve your logs.

Observability is indeed not necessarily easy to fit into a code base. Here is a potential approach to make it easier. I wouldn't use it on a project where we're only logging, but once you add metrics to the mix, this kind of probes can be worthwhile.

Very nice collection of stories from the trenches of Firefox development. Lots of lessons learned to unpack about optimizing for the right thing, tooling, telemetry and so on.