(“This Week in Glean” is a series of blog posts that the Glean Team at Mozilla is using to try to communicate better about our work. They could be release notes, documentation, hopes, dreams, or whatever: so long as it is inspired by Glean. You can find an index of all TWiG posts online.)

The last blog post:This Week in Glean: Cargo features – an investigation by Jan-Erik.

The philosophy of Glean has always been to offer higher-level metric types that map semantically to what developers want to measure: a Timespan metric type, for instance, will require developers to declare the resolution they want the time measured in. It is more than just a number. The build-time generated APIs will then offer a set of operations, start() and stop(), to allow developers to take the measurements without caring about the implementation details or about the consistency of times across platforms. By design, a Timespan will record time consistently and predictably on iOS, Android and even desktop. This also empowers the rest of the Glean ecosystem, especially pipeline and tooling, to know about the quality guarantees of the types, their format and, potentially, ways to aggregate and visualize them.