System design course

Is it good to invest money in System Design course from Gaurav Sen? So much free good quality content already available on internet.

I have 9 years of experience in software development.Is the paid course by Gaurav Sen about system design on interview ready really useful? Thinking of buying it for interview preparation.

What is best system design course available? Could you please list top 3 in order with best as 1. Also mention what type of candidates are best suited for each course. I’m currently going through interview ready- Gaurav Sen. And find it hard to follow since I have almost never done system design. Hence I find it ok-ok , are there any better ones out there? I know grokking is one more. Please provide suggestions with course name and best suited for what professionals(eg , beginner with no exposure to system design , 5 yoe with some exposure to system design , advanced with high exposure system design)

I am preparing for interviews and for DSA resource following Strivers YouTube channel and for development referring Harkirat . Can you please suggest me some resource or playlist for System design ?

I am preparing for interviews and never had any system design round before. Not sure how should I start preparing. I know there are lots of videos out there, but don't want to follow some random posts. Seen posts from bytebytego but they are most random posts . Rather looking for a way to learn systematically from scratch even though I might many of them. Looking for free resources

Suggest some sources from where i can study system design for my internship interview.. although i know interviewers rarely ask sd in any internship interview but still i want to be on safer side

To all those folks who cracked system design round in various companies. Please specify the sources which you used to learn system design, free and paid both.

Is it to sufficient to read books like Design data intensive applications and books from Alex Xu sufficient for system design interviews? If not, then what other resources would help? Thanks in advance!