Do you think these courses would be worthwhile for a seasoned software engineer?

I followed them a long while ago, they're fun but you'll probably find they move too slowly.

Seriously though, they are fun. Racket's way of programming with pictures is great. Maybe following the book at your own pace would be more rewarding.

I believe op is talking about the entire sequence where after those 2 you learn java and typescript. I also took the entire sequence the java one was really good at explaining aliasing problems, how to figure out an existing codebase by yourself, and all taught by UBC profs.

The two intro courses that use htdp are not nearly as rigorous as the book, you never get to see anything difficult enough to warrant using the design recipes where the book you begin to appreciate that style more and more as it gets harder.

The two courses of your parent comment are 2 out of 6 courses of this program [1]. It mentions Java and Typescript. It seems like all 6 can be taken for free if you click the individual links. Is this what you took?

[1] https://www.edx.org/micromasters/ubcx-software-development/

That indeed is the course the top comment is talking about.

The instructor Gregor Kiczales has a youtube channel named 'Systematic Program Design' [2]. His 5 minutes intro video [3] is really good IMO - one can send it to ones relatives or friends who ask you what the heck you are doing in your job.

[2] https://www.youtube.com/channel/UC7dEjIUwSxSNcW4PqNRQW8w

[3] https://www.youtube.com/watch?v=dJbpHukiQ7I

Yep well 5.5 courses I took as the last one is a big project and I already was doing one so skipped it. The java courses are good in teaching how to properly make an abstract object iirc, was many years ago I took them. Probably the best intro to programming sequence you can find though maybe not enough assignments

Kiczales also wrote the Common Lisp classic "The Art of the Meta-Object Protocol"

Are the 2 courses sufficient on their own? or do I need to read the book as well?

Those 2 are part of 6 courses. See my comment above:

https://news.ycombinator.com/item?id=26515981

The 2 courses are based on the book, but do not require, or even refer to the book.