Core update drops feel personal and are not. They are Google re-scoring quality across a whole category, and the first casualty of one is usually judgement: teams start changing things immediately, which destroys the baseline needed to understand what happened.
Step one: confirm it was the update
Line your traffic drop up against confirmed update dates. A decline that started three days before the rollout is a different problem, possibly a technical change, a tracking break or a seasonal shift. Diagnosing the wrong cause wastes months, and it is a common mistake.
Step two: segment the damage
Almost no site drops uniformly. Break the decline down by page type, topic and query intent. The pattern usually names the problem: commercial pages down while informational pages hold, or one content cluster hit while everything else is stable. That segmentation is the most valuable hour of the whole recovery.
Step three: assess against what the update rewarded
Core updates broadly re-weight quality and helpfulness. Compare your affected pages honestly against those now outranking you. Is theirs more genuinely useful, better sourced, more clearly authored, less obviously produced at volume? Read your own content as a stranger would, or better, have someone else do it.
Step four: fix causes, not symptoms
Improve depth and originality where pages under-answer their search. Add author credentials and real expertise signals, especially in health and finance topics. Remove or consolidate pages that exist only to target a keyword. Strengthen the pages that still perform, because concentrating quality is part of the signal.
Step five: be honest about the timeline
Recovery usually arrives with a subsequent core update, not in the weeks between them. That can mean three to six months, which is uncomfortable but true. Work that is genuinely improving quality does often show partial recovery sooner; work that is cosmetic shows none at all.
What not to do
Do not disavow links reflexively, do not rewrite the whole site at once, and do not buy your way out with a link package. Panic responses to core updates cause more lasting damage than the updates do. If you would rather have the diagnosis done independently, that is exactly what an SEO audit is for.