Ask HN: Working as a software engineer for 5 years, I've forgotten all CS stuff

I have a Bachelor of CS. But after working for 5 years, I can't remember these CS stuffs like Computer Organization, OS theories, Database normalization. What occupies my mind is delivering the feature to meet business goals and Kubernetes stuffs.

Is this normal? Or I need to work harder to learn them again?

Praxis centric knowledge base, tool set is more responsive to actual demands

It is normal. You may need to relearn what you have completely forgotten.

I try to integrate my CS education in my normal software engineering work. The work is high level, not a lot of opportunity to use theory of computer architecture or operating systems, but I'm still writing programs. This means lessons from algorithms and functional programming are relevant. Organizing code using this theory has not only retained the college lessons but reinforced them. My advice is to use the tools from your education when you can, and they will only become stronger when you do.

Yes it's normal and, dare I say, a bit of an exaggeration. Academia and industry are different environments.

A broader understanding gives your more fallback positions in the event of some disaster or catastrophic economic collapse, so I'd say:

Put a little bit of your time into learning interesting new skills in even vaguely related fields. A Jack of all trades may be a master of none, but if chaos is the future, adaptability is the key to survival.