Hi everyone ! I'm new to this forum, been doing SEO for less than a year now in Europe (english is not my mother tongue, so sorry if I sometimes use inadequate phrasing ), and what I love about it is I'm still learning a lot every day, and continuously will I hope Need help on a problem I'm facing for the first time : making big text content and internal linking modifications to a huge website (one and a half million pages). The structure of the site will not change, neither its usability (for the most part), only loads of text and image content will be replaced, and some internal linking will be reorganized (only alternative navigation). Some people tell me it's quite a gamble in terms of SEO, others don't think it's that big of a deal, so I don't know where to stand : what are the risks ? For example I guess for the text modifications it'll be important to keep alive the existing optimizations, but what if the topic of a page (and thus its keywords) shift ? Do I need to make the changes one at a time on a long time period or can I change it all in one bump ? Thanks a lot for your insights !