WordPress for a very large website

I’ve searched and searched but I did not find an answer online. Also, I’ve posted this on StackOverflow and apparently it wasn’t ok and I reposted this here. I hope it’s ok.

I have this website which is very large: a lot of articles, comments, likes for articles (not Facebook likes but own likes), ratings for articles, multiple users that each have a blog, forum, user wall, user friends etc.

My team and I made it 5-6 years ago in CakePHP and now the client wants to remake it. I thought WordPress would be a good solution given the tendency towards articles and stuff, and WordPress (at least I think) knows best about articles and stuff. I’ve checked and WordPress supports multiple blogs, I can customize the user’s fields, I can make user relations, user galleries and everything; also, I’ve done a few themes in WordPress (about 10) and I really like the way it’s coded.

Is it a good solution to remake it in WordPress? Considering about 50,000 articles and each about 100 comments and about 100,000 users (worst case scenario), would WordPress be able to render the website in less than one second (just the server side, not including CSS, JS and other stuff).

As far as I know WordPress only has like 20-30 tables (MySQL), while the website has 180 tables now. So, it will fit 180 tables worth of information into about 20-30 tables. Won’t that get too slow, crowded, etc?

Sorry for the long question, but I want to be sure I’m making the right decision. In short: for a website with a lot (and I mean a lot) of content and a lot of traffic, is WordPress a viable solution?

…would WordPress be able to render the website in less than one
second…

WordPress is perfectly scalable to the amount of content and user base you’re describing.

You just need the horsepower for httpd (apache/nginx) to be able show one second page loads and have the database server (mysql, maria) respond fast, too.

You also need to configure the server – using various httpd and mysql utilities – to handle the loads, as well as work with php configs and opcode caching.

There is already all kinds of information out there on high performance WP sites and scalability: http://www.google.com/search?q=is+wordpress+scalable

There are too many options to cover here; many will depend on the server, the host, and on and on. https://serverfault.com/ is much better for server questions, as much of the time, they won’t be WordPress-specific.