What's causing the sudden increase in failed transactions for USD to EUR transfers over Wise in the past week?

Introduction

The sudden increase in failed transactions for USD to EUR transfers over Wise in the past week is a critical issue that demands immediate attention. As we analyze this product problem, we'll follow a systematic framework to identify, validate, and address the root cause while considering both immediate and long-term implications.

I'll approach this issue by first clarifying the context, then ruling out external factors before diving deep into the product mechanics, metric breakdown, and data analysis. We'll generate hypotheses, conduct root cause analysis, and propose validation methods and solutions.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this could be related to recent changes. Have there been any system updates or deployments in the last two weeks?

Why it matters: Recent changes often correlate with sudden performance shifts. Expected answer: Yes, a minor update to the transaction processing system. Impact on approach: If true, we'd focus on regression testing and rollback considerations.

• Considering user segments, I'm curious about the distribution. Is this increase in failed transactions uniform across all user types, or is it more pronounced in specific segments?

Why it matters: Helps narrow down potential causes and affected user groups. Expected answer: More prevalent among high-volume business users. Impact on approach: We'd investigate business-specific features or limits if confirmed.

• Given the nature of currency transfers, I'm wondering about external factors. Have there been any significant EUR/USD exchange rate fluctuations or regulatory changes recently?

Why it matters: External economic factors can significantly impact cross-border transactions. Expected answer: No major changes noted. Impact on approach: If true, we'd focus more on internal systems and processes.

• Thinking about system health, I'm concerned about potential infrastructure issues. Have we observed any unusual patterns in server load or response times coinciding with the increase in failed transactions?

Why it matters: Infrastructure problems can manifest as transaction failures. Expected answer: Some intermittent latency spikes noted. Impact on approach: We'd prioritize infrastructure and capacity analysis if confirmed.