Interview Questions › Root Cause Analysis

Push notification click-through rate has declined recently

Overall click-through rate (CTR) on retention push notifications dropped from 8.2% to 5.4% over the last month. Find the root cause.

Context

Daily push send volume increased by 25% due to a new engagement experiment targeting dormant learners.

Clarifying questions to ask first

• Did opt-out / notification disabling rates also increase?
• Which user cohorts experienced the steepest drop?

How to approach it

1. Segment push types (Streak Reminders, Social Leaderboard, Promotional, New Course content)
2. Analyze deliverability (iOS Focus Mode / Android 13+ Notification Permissions)
3. Assess notification fatigue and send frequency per user per day
4. Evaluate copy personalization and timing algorithm effectiveness

Framework: Notification Frequency & Fatigue -> Segmentation by Push Category -> Platform Permission Changes -> Send Time Optimization

Sample answer

• Over-messaging fatigue from multiple concurrent team campaigns
• iOS notification summary grouping reducing instant glanceability
• Decline in copy relevance for dormant cohort

1. Break down CTR by push category: Streak reminders steady at 11%, but new "Friend Activity" broadcast had a 1.2% CTR and fatigued users
2. Total pushes per active user increased from 2.1 to 4.2 per day

Push fatigue due to overlapping marketing campaigns; implemented global messaging frequency capping (max 2/day) and prioritized high-CTR streak alerts.

What interviewers look for

• Push CTR (%)
• Push Opt-Out Rate
• Sends per User / Day
• Time-to-Open Distribution