NestJS Observe
I like this one because observability is still a sore spot for most Node shops. You can build a beautiful NestJS API in a weekend, and then spend another two weeks wiring up OpenTelemetry, trying to get traces to actually show up, and fighting with your logging library. A tool that says zero-config out of the box is basically promising to kill that whole second phase.
The bet here is that NestJS's opinionated structure makes this possible. Since the framework already controls the request lifecycle, dependency injection, and middleware, there's a real chance to instrument everything without the user lifting a finger. That's a smarter approach than bolting a generic agent onto whatever Express app happens to be running underneath.
I'd want to know how deep it goes, whether it captures database queries, queue consumers, and background jobs, or just HTTP routes. And I'd be curious about the pricing model, because zero-config tools have a habit of being free until you hit a certain volume of requests. Still, if it works as advertised, this could be the default choice for new NestJS projects. That's a compelling wedge into a fast-growing developer base.