Computer Science Project Ideas

I know this question has been asked previously, but I feel this question is an ongoing question as every year new ideas come into mind. So please do not flag this question as repeated.

More importantly many people who ask this question tend to get confused about this question, and hence give out wrong suggestions.

What is Computer Science?

"Philosophy, logic, and mathematics applied to describing what we can compute, how we can compute, and how fast we can compute. The more theoretical parts of computer science answer questions about the limits of computation by proving what is possible and what is impossible. The more applied parts of computer science design answer these questions by building proofs of concept."

So please please please, do not recommend answers like UI/UX design, or general website projects.

What I really want to see in answers section is project ideas that really reflect on computer science, rather than design or anything related.

I want to be able to get my hands on algorithms, its complexity, upper bound/lower bound etc...

For example, I had an idea of combining data mining and web tech together to be able to get users search history about their current situation (i.e. looking for work, studying, modules, holiday, literally everything) and predict answers for them in a graphical way. But I'm not too sure of the idea.

Can anyone please recommend any ideas? I really wanted to do something with data mining and web tech. Especially for anyone looking for projects like my self (as there is no current website that provides this)

Thanks Guys!