Analytics instrumentation glossary

A line of code that emits an event to an analytics backend like PostHog, Mixpanel, Segment, Amplitude, Heap, or Snowplow.

The string identifier passed to an analytics call, used to group occurrences of the same thing on a dashboard.

The object passed alongside the event name, carrying contextual properties that get attached to the event on the analytics backend.

The call that ties subsequent events to a known user identity, typically by mapping an anonymous ID to a real user ID.

The set of event names and properties a product agrees to emit, and the rules for naming them.

The total set of analytics calls in a codebase. The thing Skene reads, indexes, and watches for drift.

The recorded state of an instrumentation surface at a point in time, used as the comparison point for future PRs.

Unintended changes to analytics calls between two states of a codebase. Often introduced by refactors or coding agents.

A diff between two states that compares meaning, not text. The kind of diff Skene runs on instrumentation manifests.

An analytics call that existed in the previous version of the codebase and no longer exists in the new one.

An analytics event whose name string changes between two states of the codebase, splitting funnels across two names.

An analytics call that still exists in the codebase but now fires from a different control-flow context than before.

A change to the properties object of an analytics call: renamed key, dropped key, or changed type.

A change to the if-block guarding an event. The event still fires, but for a different set of users or sessions.

A tool that ingests events from your app and fans them out to multiple downstream destinations. Segment, RudderStack, Hightouch Events.

A central catalogue of event names and payload shapes that an analytics team agrees to. Sometimes called a tracking plan.

An open protocol for letting AI agents call out to external tools. Skene exposes its validation engine as an MCP server.

An AI tool that reads and writes code: Cursor, Claude Code, Codex, Devin, Aider. The category Skene is built to live alongside.

Code that affects something outside the function it lives in. Analytics calls are side effects. So are logs, emails, and metric increments.

A sequence of events users move through. The chart most teams check daily; the chart most affected by instrumentation drift.

An event that represents a desired outcome - usually tied to revenue. The most expensive thing to lose instrumentation on.

The event that marks when a new user reaches first value. Usually one of the most-watched metrics in product orgs.

A group of users defined by a shared property or behaviour. Most retention analysis runs on cohorts.