Why did Netflix My List update time increase to 10 minutes?

Introduction

The sudden increase in Netflix's My List update time to 10 minutes is a critical issue that demands immediate attention. This unexpected performance degradation could significantly impact user experience and engagement with a core feature of the platform. I'll approach this problem 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)

• Looking at the timing, I'm thinking this might be a recent change. When exactly did you first notice this increase in update time?

Why it matters: Pinpointing the timeframe helps narrow down potential causes. Expected answer: Within the last week or two. Impact on approach: A sudden change suggests a recent system update or infrastructure issue.

• Considering user segments, I'm wondering if this affects all users equally. Have you noticed any patterns in terms of user demographics or device types experiencing this issue?

Why it matters: Identifying affected segments can help isolate the problem. Expected answer: The issue appears to be widespread but may vary by region or device. Impact on approach: If segmented, we'd focus on specific user groups or technical environments.

• Given the nature of the feature, I'm curious about the content volume. Has there been any significant change in the average number of items in users' My Lists recently?

Why it matters: An increase in list size could impact processing time. Expected answer: No substantial change in average list size. Impact on approach: If unchanged, we'd look more closely at backend processes or infrastructure.

• Thinking about recent updates, have there been any changes to the My List feature or related backend systems in the past month?

Why it matters: Recent changes are often the culprit in sudden performance issues. Expected answer: A backend update was deployed two weeks ago. Impact on approach: We'd prioritize investigating the recent update and its impact.

• Considering the metric itself, I'm wondering about the measurement process. Has there been any change in how we measure or define the "update time" for My List?

Why it matters: Ensures we're comparing apples to apples in our analysis. Expected answer: No changes to the measurement process. Impact on approach: Confirms the issue is with the actual performance, not the measurement.