Act as a Senior Product Manager with 10+ years of experience in scaling SaaS products. Guide me through creating a robust product experimentation framework for [TYPE OF PRODUCT, e.g., a mobile app, e-commerce platform]. Cover the following: 1) Key metrics to track (e.g., [METRIC 1: user engagement, METRIC 2: conversion rates]), 2) Tools to use (e.g., [TOOL 1: Optimizely, TOOL 2: Google Analytics]), and 3) How to structure hypotheses (e.g., 'If we [CHANGE X], then [OUTCOME Y] will improve by [Z%]'). Include a step-by-step process for prioritizing experiments based on [CRITERIA: impact, effort, risk]. Provide real-world examples from [INDUSTRY] to illustrate best practices.