What's causing the sudden increase in failed API calls for Cellulant's merchant integration service?

Introduction

The sudden increase in failed API calls for Cellulant's merchant integration service is a critical issue that demands immediate attention. This problem could significantly impact merchant operations, customer satisfaction, and Cellulant's reputation in the fintech space. I'll approach this analysis systematically, focusing on identifying the root cause, validating hypotheses, and developing both short-term fixes and long-term solutions.

Step 1

Clarifying Questions (3 minutes)

• Given the sudden nature of the increase, I'm thinking there might have been a recent change. Has there been any recent deployment or system update in the last 24-48 hours?

Why it matters: Recent changes are often the culprit in sudden performance shifts. Expected answer: Yes, there was a minor update to the API gateway. Impact on approach: If confirmed, we'd focus on the recent changes first.

• Considering the potential scope, I'm curious about the scale. What percentage increase in failed API calls are we seeing compared to the baseline?

Why it matters: The magnitude helps prioritize the issue and gauge its impact. Expected answer: A 30% increase in failed calls. Impact on approach: A significant increase would warrant more urgent action.

• Looking at user segments, I'm wondering if this is affecting all merchants equally. Are we seeing any patterns in terms of merchant size, location, or integration type?

Why it matters: Segmentation could reveal if it's a targeted issue or system-wide. Expected answer: Smaller merchants seem more affected. Impact on approach: This would guide our investigation towards specific integration points or scalability issues.

• Thinking about potential external factors, have there been any significant changes in transaction volumes or patterns recently?

Why it matters: External events could be straining the system beyond its normal capacity. Expected answer: Transaction volumes have been stable. Impact on approach: If volumes are stable, we'd focus more on internal system issues rather than capacity problems.