[0] https://nedbatchelder.com/text/bigo.html
[1] https://nedbatchelder.com/blog/201711/toxic_experts.html
I'll double down on my toxicity by saying I didn't like the page layout. As someone with ADHD (and a declining memory), I need to be led through formatting/sub-headings/bullets/colored sections/etc into each detail or it all blends together into a wall of text. The longer it takes to make a point (visually and conceptually), the more lost I am. I couldn't easily follow it. The Simple Wikipedia page was more straight to the point (https://simple.wikipedia.org/wiki/Big_O_notation), but reading the "full" Wikipedia page thrusts you headlong into a lot of math, which to me signifies that this shit is more complex than it seems and simplifying it is probably a bad idea.
If you say, “hash maps are generally O(1), and are a great default choice,” you’re not that wrong (subjectivity aside).
If you say, “storing integers as strings guarantees precision, so you should prefer them over decimal or float types,” you’re technically correct about the first part, but are enormously wrong for a variety of reasons about the conclusion.