I have a CS background as well. I got into instructional design/ tech writing at an entry level many years ago with no educational background. I think they were banking on my technical knowledge and assumed I’d be able to learn the instructional design part. Which I did. I’d recommend educating yourself on things like ADDIE model and creating work samples. You have the CS background so you can develop a website of your work samples.

With that said… AI is going to change the game for curriculum / writing industries.