What's causing the sudden increase in failed transactions for SnapScan's peer-to-peer money transfer service?

Introduction

The sudden increase in failed transactions for SnapScan's peer-to-peer money transfer service is a critical issue that demands immediate attention. This analysis will systematically identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

I'll approach this problem by first clarifying the context, then ruling out external factors before diving deep into the product ecosystem, metric breakdown, and data analysis. From there, I'll form and validate hypotheses, conduct root cause analysis, and propose a comprehensive resolution plan.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this could be a recent change. When exactly did you first notice this increase in failed transactions?

Why it matters: Pinpoints the timeframe for investigation Expected answer: Within the last week or month Impact on approach: Narrows down potential causes to recent changes

• Considering user segments, I'm wondering if this is widespread. Are all user groups equally affected, or is there a particular segment experiencing more failures?

Why it matters: Helps identify if it's a systemic issue or specific to certain users Expected answer: Affects all users, but possibly more pronounced in high-volume users Impact on approach: Focuses investigation on common factors vs. segment-specific issues

• Given the nature of peer-to-peer transfers, I'm curious about the transaction flow. At which stage of the transaction process are these failures occurring most frequently?

Why it matters: Isolates the problem area within the transaction flow Expected answer: Failures occur at the payment processing stage Impact on approach: Directs attention to specific components of the system

• Thinking about recent changes, have there been any updates to the app, backend systems, or third-party integrations in the timeframe preceding this issue?

Why it matters: Identifies potential triggers for the problem Expected answer: Recent update to payment processing API Impact on approach: Focuses on recent changes and their implications

• Considering the metric itself, has there been any change in how failed transactions are defined or measured recently?

Why it matters: Ensures the observed increase is real and not due to measurement changes Expected answer: No changes in definition or measurement Impact on approach: Validates the issue as genuine and not a reporting anomaly