Feature Validation: Ordering Multiple Accounts by Unread Notifications

Context

Users can hold multiple accounts and switch between them. The product team proposes to order a user's accounts by descending count of unread notifications to help them find the next most relevant account quickly.

Definitions (for clarity):

• Account switching: The user changes from one account to another within a session.
• Active account (per period): An account with at least one meaningful action (e.g., session, post, message, read/clear notification) in the period.

Tasks

1. Using data, outline how you would assess whether prioritizing accounts by unread-notification count is a worthwhile idea before shipping (e.g., exploratory/historical analyses, segmentation).
2. Design an A/B test to validate the feature. Specify:
   • Population and unit of randomization
   • Treatment and control
   • Primary and guardrail metrics (with rationale)
   • Test duration and power considerations
3. The hypothetical result shows: frequency of account switching drops, while total number of active accounts rises. Interpret this outcome and propose next steps.

Hints

Consider exploratory historical analysis, customer behavior segmentation, primary vs. guard-rail metrics, experiment power, and how to reconcile conflicting short-term and long-term signals.