Google Analytics also showed a corresponding drop in traffic, which meant something was definitely on the rise. As an SEO, I naturally prepared for the worst...
Step 2: Algorithm Panic
I clicked on Barracuda's Panguin tool to see if our issue coincided with the confirmed update.
And no updates.
Step 3: Diagnose the problem
I finally came to my senses and figured out what was going on: it was extremely rare for keyword rankings to disappear completely, and it had to be technical.
It must be an index.
A quick Google search for the pages that lost rankings for their keywords confirmed that the pages were, in fact, gone. Search Console reported the same thing:
Note the warning at the bottom: 'no-index' detected new zealand mobile database in 'robots' meta tag
Now we are a little bit closer. Next, it is time to confirm this discovery in the source code.
Our pages are marked for de-indexing. But how many pages have actually been de-indexed so far?
Step 4: Investigate the damage
It was confirmed that a deployment on Thursday evening August 1, 2019 accidentally pushed the noindex code onto every page.
But is the entire site de-indexed?
This is unlikely, because in order to do this, Google would have to crawl every page of the site within three days to find the “noindex” tag. Search Console is of no help in this regard, because its data is always outdated and may never change until the change is fixed.