Describe a time organic traffic dropped. How did you diagnose it?

Work through possible causes in order of likelihood rather than assuming an algorithm update.

• Is it real, or a measurement problem? Check whether tracking broke, whether a filter changed, and whether the comparison period is seasonally comparable. This costs five minutes and saves days.
• Is it site-wide or page-specific? A drop confined to one section points at something you changed there; a site-wide drop points at technical or algorithmic causes.
• Technical causes. Check for a stray noindex, a robots.txt change blocking crawlers, a botched migration with missing redirects, server errors, or a certificate problem. These are the most common causes of a sharp drop and the most fixable.
• Manual actions and Search Console messages — check immediately.
• Algorithm update. Compare the drop date against known core update dates and industry chatter. If it aligns and competitors moved too, the cause is likely algorithmic.
• Competitive or SERP change. Someone outranked you, or Google added a feature that pushed organic results down.

Note: Use Search Console's impressions and average position rather than traffic alone. Impressions steady with clicks falling means a SERP or title change, while impressions falling means a ranking or indexing problem — that distinction saves a great deal of wasted work.