What's causing the sudden increase in failed transactions on iKhokha's payment gateway over the past week?

Introduction

The sudden increase in failed transactions on iKhokha's payment gateway over the past week is a critical issue that demands immediate attention. As we delve into this product root cause analysis, we'll systematically investigate potential factors contributing to this problem, validate our hypotheses, and develop a comprehensive plan to address the issue.

I'll approach this analysis by first clarifying key details, ruling out external factors, and then diving deep into the product's user journey and metrics. We'll generate data-driven hypotheses, conduct a thorough root cause analysis, and propose validation methods and solutions. Throughout this process, we'll consider both immediate fixes and long-term strategies to prevent similar issues in the future.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking there might be a recent change in the system. Has there been any significant update or deployment to the payment gateway in the past two weeks?

Why it matters: Recent changes often correlate with sudden performance shifts. Expected answer: Yes, there was a minor update to the payment processing algorithm. Impact on approach: If confirmed, we'd focus on regression testing and code review.

• Considering the nature of failed transactions, I'm curious about the error messages. What specific error codes or messages are users encountering during these failed transactions?

Why it matters: Error codes can pinpoint specific failure points in the transaction process. Expected answer: A mix of "Connection Timeout" and "Invalid Card" errors. Impact on approach: This would guide our technical investigation towards network issues or card validation processes.

• Given the sudden increase, I'm wondering about the scale. What's the percentage increase in failed transactions compared to the previous week?

Why it matters: The magnitude of the increase helps prioritize the urgency of our response. Expected answer: A 30% increase in failed transactions. Impact on approach: A significant increase would warrant immediate action and possibly a rollback of recent changes.

• Thinking about user segments, I'm curious if this issue is affecting all users equally. Are there any patterns in terms of user demographics, transaction amounts, or payment methods that are more prone to failures?

Why it matters: Identifying patterns can help narrow down potential causes and target our solution. Expected answer: Higher failure rates for international transactions and new users. Impact on approach: This would lead us to investigate cross-border payment processes and onboarding flows.