Ask HN: Computer science heavy fields

I am a fullstack web developer. I write build and manage servers in python, or javascript. I write frontends with any of a host of frameworks. I setup logging, and monitors, and CI/CD pipelines.

I slowly refine the process and the product, a little each day.

I have a degree in engineering and I rarely if ever use what I learned. Everything I use is backed by core CS, but us consumers needn't even really know about that. Is the majority of web development like this? Or am I caught in an anomaly?

On top of that, these web-apps we put up are so fragile. Hot one year, archived the next. What fields are more long lasting? Where is the important work being done?

..please don't say blockchain.