Interview Questions › Root Cause Analysis

Orders are down 15% WoW, but traffic is stable

Weekly completed orders plummeted 15% week-on-week, but total unique visitors and page views are flat. Diagnose why shoppers are browsing without purchasing.

Context

Marketing spend, seasonal weather, and pricing catalogs are consistent with the previous month.

Clarifying questions to ask first

• Which specific step in the checkout funnel showed the steepest drop?
• Is the drop across all product categories or specific fashion apparel?

How to approach it

1. Deconstruct the E-Commerce Purchase Funnel: Home -> Search/Category -> Product Detail Page (PDP) -> Add to Bag -> Checkout -> Payment Success
2. Isolate the exact funnel drop-off step
3. Investigate inventory availability (out-of-stock sizes on bestsellers), shipping cost display changes, and checkout bugs
4. Segment by Platform (iOS vs Android vs Web), Geography, and Payment Method

Framework: Funnel Step-by-Step Isolation -> Inventory & Out-of-Stock Analysis -> Pricing & Delivery Fee Friction -> Technical Checkout Failures

Sample answer

• Increased minimum free shipping threshold from $30 to $50
• Top 20 revenue-driving summer fashion SKUs went out of stock in popular sizes (M/L)
• Promo code validation failure throwing an unhandled error at checkout

1. Funnel shows: PDP-to-Cart is normal (18%), but Cart-to-Checkout dropped 35%
2. Investigation reveals: A new delivery fee calculator was placed on the cart screen, showing high international delivery surcharges before address entry

Premature delivery surcharge calculation on cart screen shocked buyers into abandonment; rolled back cart widget to restore order conversion.

What interviewers look for

• PDP -> Add to Bag %
• Add to Bag -> Checkout %
• Payment Success Rate
• Out of Stock Impression Rate