Korean, Computer Science and Maths Degree

Something you should be aware of is that the maths covered in a maths degree (and in the maths half of a joint honours course) is very different from the kind of maths you'll have done at A-level. If you like the kinds of mathematical methods you've studied in A-level then you will cover plenty of that kind of maths in any STEM degree, including CS. Only pick a joint maths and CS degree if you are specifically interested in the much more abstract, theoretical aspects of maths, as that is what you study in a maths degree. The maths covered there will be as indicated, very abstract and mostly proof based.

In terms of Korean, learning the (or any modern) language is going to be a different experience with not necessarily the same goals as doing a degree in Korean. Modern language degrees are not merely language attainment programmes, and you will spend a lot of your time in a modern languages degree studying the history, literature, politics, and culture of the country/countries speaking the target language. If you only want to learn Korean so you can use it as a professional language then doing a Korean degree isn't strictly necessary and may not even be the best option for you. If your aim is to work in Korea then you should be aware that just speaking the language is a minimal prerequisite and you're probably going to need to demonstrate you have some desirable skill(s) for employment in sectors that the Korean government want to attract foreign talent into to get a visa.

That said you don't seem that keen on CS (or maths) outside of some vague sense that it "seems" it'll be more employable. However merely having a degree in CS isn't enough to get a job, and in fact CS degrees have below average employment prospects in the UK - so much so that the government commissioned an inquiry into the matter. I suspect part of the issue may be that so many people seem to think they can just get a CS degree and they will be given a job on a silver platter without having to do anything more than show up to lectures and exams. The fact of the matter is, this is not (nor I believe has ever been) the case.

Employers want to see more than anything that you have gained a good amount of practical, professional experience through internships, work placements, vacation scheme type things etc (this is true of any graduate role realistically actually), and that you have document your work in these, as well as in your course and any self-directed projects, to form a portfolio of programming projects that you can showcase on GitHub or similar. If your major attraction to CS is because you think it's better for employment then I'd suggest just picking a degree you are genuinely interested in (Korean or otherwise) because for generalist grad schemes outside the computing sector it's not going to be better or worse, and you will need to be putting in a lot of effort to distinguish yourself enough to be employable within the computing sector.

@umbrellala might be able to offer some advice or insight into the prospect of doing Korean at uni, while @Blue_Cow or @shadowdweller might be able to give some more insight into studying CS and working in the computing sector

Thank you this is really insightful, I guess it is worth specifying my goals for each. When it comes down to it my passion is Korean and if I studied it I would want more than just to speak it id love to translate, teach (at a high level), maybe interpret, the list is endless, the main thing is that I wouldn't want the degree to then just go into a bank per say and then speak korean to people every now and then I would go for a more concentrated field where I would be dealing with it every day. A counter-argument could be to do the Computer science and maths degree but then take some TOPIK exams after but maybe that wont be enough to secure a job in languages at a advanced level compared to those who have a degree.

On the Computer science and maths side of it, I do enjoy problem solving and theoretical maths the abstract part isn't what i'm worried about, I find it interesting learning about things in Further Maths but I don't come home wanting to do more it's more of a thing that I know that if I put my mind to it I can become very good at it (This here is one of the only reasons why this has become such a hard decision for me), its the fact that I also like coding quite a bit I know this from doing it at gcse and then messing around with code in python and C++ in my spare time in college. I would want to be something like software engineer (or a programmer more generally) where I would code, obviously there is more to it but coding is a big factor. However I am thinking if it is just the code, is it worth it just to learn that in my spare time or through a certificate I can gain through a site online or a bootcamp.

And this is where my trouble lies, I am super passionate about Korean and languages in general, but am trying to be practical about the money and the stability, but then at the end of the day I know I would be happier in a language job.

You can always study Mathematics or Computer Science and then work abroad in Korea. That would offer the most flexibility in terms of job roles and you can always learn Korean without going to university too.

I think the final sentence really tells you your answer; you would rather be doing language work by the sound of it! If it's only the programming side of CS that is of interest to you then you can just as well learn that yourself outside of a CS degree anyway. It may well even be possible to incorporate it into e.g. a dissertation in a Korean degree by doing some kind of computational corpus linguistics project where you write a program to hand some linguistic data or something.