What can cause TTFB to jump?

Question

Client side optimization

Hello everyone, I have a site - I'm optimizing it for the needs of the client -

Now TTFB is in the greenline, but when the site is first loaded (sometimes) TTFB shows 400-500? I understand it's all about the cache? Or is it a problem with the server? Or a banal error and TTFB always shows a floating number and not bother?

Answer 1

Hosting server overload.