What caused the sudden spike in error rates for Coveo's Query Suggestions API last week?

Introduction

The sudden spike in error rates for Coveo's Query Suggestions API last week is a critical issue that demands immediate attention. As we delve into this product execution problem, I'll employ a systematic approach to identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this could be related to a recent deployment. Has there been any significant update or change to the Query Suggestions API in the past week?

Why it matters: Recent changes often correlate with performance issues. Expected answer: Yes, there was a deployment on Tuesday. Impact on approach: If confirmed, we'd focus on changes in that deployment.

• Considering the nature of the API, I'm wondering about usage patterns. Have we seen any unusual spikes in query volume or changes in query complexity recently?

Why it matters: Unusual load can strain systems and expose vulnerabilities. Expected answer: Query volume has been stable, but complexity has increased. Impact on approach: We'd investigate why queries are becoming more complex and how this affects the API.

• Given that it's an error rate increase, I'm curious about the specific types of errors we're seeing. Are these primarily timeouts, incorrect suggestions, or something else?

Why it matters: Different error types point to different root causes. Expected answer: Mostly timeouts with some incorrect suggestions. Impact on approach: We'd focus on performance optimization and data accuracy.

• Thinking about our infrastructure, I'm wondering if there have been any changes to our backend systems or data sources that feed into the Query Suggestions API?

Why it matters: Backend changes can have cascading effects on API performance. Expected answer: No major backend changes, but a data refresh occurred last week. Impact on approach: We'd investigate the impact of the data refresh on query processing.