Hey Geno, sure thing. I was planning on writing a separate blog for those, but haven't had time while starting the new job!

For ML Design, I only read Alex Xu's ML System Design book, and I didn't even finish it. It was a pretty good resource, and I think I could've passed E4 with only that resource. For system design, I used Alex Xu's System Design Interview book to begin with, but halfway through I switched to HelloInterview blogs. I feel like HellowInterview was by far the best resource for system design, so I would recommend start there!