measure-instrumentation-spec

<!-- PM-Skills | https://github.com/product-on-purpose/pm-skills | Apache 2.0 --> # Instrumentation Spec An instrumentation spec defines what analytics events to track, when to fire them, and what properties to include. It serves as a contract between product and engineering, ensuring consistent data collection that enables accurate measurement. Good instrumentation specs prevent the "we can't answer that question because we didn't track it" problem. ## When to Use - Before engineering implements a new feature - When defining analytics requirements for experiments - When auditing existing tracking for gaps or inconsistencies - When onboarding a new analytics tool - Before launch to ensure measurement is in place ## Instructions When asked to create an instrumentation spec, follow these steps: 1. **Define Analytics Goals** Start with the questions you need to answer. What will you measure? What decisions will this data inform? This prevents over-instrumentation while ensuring nothing important is missed. 2. **Identify Events to Track** List each user action or system event that should be tracked. Follow consistent naming conventions (typically `noun_verb` or `verb_noun` in snake_case). Each event should represent a distinct, meaningful action. 3. **Specify Event Triggers** For each event, describe exactly when it fires. Be precise: "When user clicks Submit button" vs. "When form is submitted successfully." These are different events with different meanings. 4...