What's causing the sudden increase in failed transactions for Revolut's international money transfer service?

Introduction

The sudden increase in failed transactions for Revolut's international money transfer service is a critical issue that demands immediate attention. As we delve into this problem, we'll employ a systematic approach to identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

Our analysis will follow a structured framework, covering issue identification, hypothesis generation, validation, and solution development. This approach ensures we leave no stone unturned in our quest to resolve the problem and prevent future occurrences.

Step 1

Clarifying Questions (3 minutes)

• I'm noticing a sudden increase in failed transactions. Would you say this spike occurred within the last 24-48 hours?

Why it matters: Timing helps identify potential triggers and narrows the scope of investigation. Expected answer: Yes, the increase was noticed in the last 24 hours. Impact on approach: Recent changes would be prioritized in our investigation.

• Given Revolut's global presence, are we seeing this issue across all regions or is it concentrated in specific areas?

Why it matters: Geographical patterns could point to localized issues or regulatory changes. Expected answer: The issue is primarily affecting transfers to and from certain regions. Impact on approach: We'd focus on region-specific factors and potential regulatory changes.

• Has there been any recent update to the money transfer system or related infrastructure?

Why it matters: Recent changes are often culprits in sudden performance shifts. Expected answer: A minor update was pushed to production yesterday. Impact on approach: We'd prioritize investigating the impact of this recent update.

• Are all types of transfers affected equally, or is there a discrepancy between different currencies or transfer amounts?

Why it matters: This helps identify if the issue is systemic or specific to certain transaction types. Expected answer: Large transfers and certain currency pairs are more affected. Impact on approach: We'd focus on these specific transaction types and investigate potential currency-specific issues.

• Has there been any change in the definition of 'failed transaction' or in the systems measuring this metric?

Why it matters: Ensures we're not dealing with a measurement anomaly rather than an actual increase in failures. Expected answer: No changes in definition or measurement systems. Impact on approach: We'd rule out measurement issues and focus on actual transaction failures.