Defining Success Metrics for a Feature

Summary

Before building anything, deciding in advance what 'this worked' will look like numerically — so you're not tempted to retroactively pick a metric that makes the launch look good.

• 1Pick a feature idea and write its success metric and target threshold before any data exists.
• 2Separate your primary metric from 2-3 guardrail metrics (things that shouldn't get worse).
• 3Practice defending your chosen metric against the question 'why not measure X instead?'