I have a client we have been working with for sometime. Our client's ranking was fantastic, until an API we've integrated long ago into the site slowed down links to 45 seconds, in which harmed our ranking for the site. We resolved this issue however (after two weeks of work) and it has been fixed for 3 months now. Our ranking has not bounced back, and in fact googling the client's name does not bring up the site on the first page. This issue with the API was the only variable in which was changed that brought the ranking down, and I am concerned why it has not found it's way back to it's original position.
However, I've notice we have multiple 404 to pages that do not exist on the site itself, most links/pages being images. However, to my knowledge, such 404's do not harm any sort of SEO management according to Google.
We've also request Google to crawl the site, in which it seems not to be indexing any of it.
My question is, why is it taking so long for our client's site to bounce back, and is there anything more we can do to aid it in order to bounce back.