I have graduated a year ago from Oxford with a first honour master's degree in maths and computer science. Since then I've been trying to find a decent job and have been failing, to the point where I feel like going back into academia is my only option.
During university I focused so much on my studies that I missed out on any internships or graduate positions I could have applied for (in the UK, you apply to graduate jobs during the first term of your final year). When I graduated, I tried applying to any entry-level jobs available to me that looked even remotely interesting and paid >30k. Out of three hundred applications, I got two interviews: one to Jane Street during which I have gotten to the last on-site stage and failed due to not being the best quick thinker, and one to the company I work at right now and desperately want to quit.
My current job is the most dead-end software development job imaginable; I work fifty hour weeks, doing things that any high schooler with an eight-week course in web development can do and I am bored out of my mind. Due to this I've been looking to quit and been trying to find a new job for the last month. Again, out of more than hundred applications (all to entry-level/graduate jobs), not even a single interview invite.
On the other hand, I loved the quantum computing in university and submitted eight applications for PhD positions in that field, which resulted in three interviews and two offers, from Nottingham and Cambridge. This makes me think that skills I have are much more sought after in academia. But after thinking about it for a while, I realised that I dread getting into an academic career – having minimal pay, having to teach five classes just to survive. Moreover, I believe that the particular topic I'm interested in is not very transferable to other careers, and so after I graduate with a PhD in four years, my job prospects will probably look just as grim if not worse than they do now, instead I will also be approaching my thirties and probably balding. What should I do?
"Out of three hundred applications, I got two interviews"
You are doing something wrong. By sheer numbers you should have gotten more feedback than 2 of 300, let alone with an honours degree from Oxford in Math. I suggest you head over to workplace.stackexchange.com to get help on your application game, b/c something is clearly not working out...