What Google will do if my webpage display 404 for one day only?

Hey everyone, what happened is one of my websites was troubling so I assigned a developer to look into it and don't know what she did.. the website is fully gone after this. Then I assigned a new developer to fix it. It took 15 days and he restored the home page but other pages started displaying 404. It was just for one day only. I again called the developer and he fixed everything in just 24 hours. But for my loss.. the ranks of the keywords are gone now. Keywords ranking for 1 on the first page are now in the 20s and 30s. Can you say what would have happened. I know Google downgrades the ranks when a page shows 404 but not sure it happens so soon or if it was an effect of 15 days shut down of the website. Please help. I don't have permission to post on other forums so I posted it here. Sorry!

Yes your site was shutdown for 15 days is the cause of the issue. But you will get back the rankings in most cases. You just need to be patient

Start validation for 404 errors in GSC. Your rankings should return to normal within a few days.