I was very depressed at my job for similar reasons (albeit in research rather than as a developer), and I definitely had trouble making progress. One thing that really helped for me was exploring what other people in other research groups were working on. I ended up discovering that other people in my lab were doing awesome things with machine learning (which I had no experience with but found to be really cool).

I decided to put in the bare minimum effort doing the grunt work I was assigned to do normally, and used my free time at work and at home to study machine learning / data science and to speak with the other research team to develop a background in their project. The topic switch and sense of purpose changed my outlook on the job entirely, and after demonstrating that I could add value to their project, this other research group was able to convince my boss to transfer me to their project which has been awesome and led to many cool opportunities.

I would encourage you to explore what other people at your job are working on. Maybe you can move laterally into a role which you find to be more interesting, or at least discover an opportunity to build interesting skills.