wtf is telemetry.rs?

This library helps developers track how their application is actually performing in the real world. Instead of just guessing whether code is fast or slow, it collects real measurements, like how long operations take, whether features are actually being used, or how much disk activity happens, and either saves that data locally or sends it to a server where it can be analyzed for patterns and problems. The core idea is simple: you define what you want to measure (called a Histogram), the library collects the data as your application runs, and then you decide what to do with it. You might save measurements to a file for later review, or stream them to a remote server that can spot when performance gets worse. This is especially useful for catching regressions, when a new code change accidentally makes something slower or breaks a feature people depend on. Practical examples of what you'd use this for include timing how fast a database query completes, counting how many times a user clicks a button to see if they care about that feature, tracking how long a user's session lasts, or measuring how much reading and writing your app does to disk. You could also record what operating system someone is using or what settings they've chosen, giving you a richer picture of your user base and how they interact with your application. The library is designed in Rust, a programming language known for being both fast and safe, which makes it a good fit for performance monitoring. It provides different types of measurement containers suited to different kinds of data, so you're not forced into a one-size-fits-all approach. Once measurements are collected, exporting them is flexible, the data can go wherever your application needs it to go.