The stories I hear from friends in HR, at varying company sizes, is the stuff of fiction. Apparently most people apply with utter trash, its no surprise they get filtered out if they can't even be bothered to present themselves properly.
At least at smaller companies, if you have something that actually looks like you tried, you immediately stand out. (After HR waded through all the bad ones)
We are also not talking about typos or gaps in the CV here, but things like: including everything expected in a CV, writing something even vaguely resembling a formal letter, or even, addressing the right company in it (bonus points if they are a direct competitor).
Another "trick" (common sense from my point of view) is to schedule if possible the first interview in the middle of the week. Typically I would schedule for a Wednesday/Thursday so that the second interview can land on the next Monday or Tuesday, that gives me at least 4-5 days to prepare for it. I try to avoid first interviews on Mondays because then it's more difficult to schedule something for the following week. I also notice that interviews with engineers scheduled in the afternoon (between 2 and 4pm) are rather "softer" than those in the mornings (I don't know why, perhaps everyone is just a bit sleepy after lunch perhaps?). I wear a white t-shirt to avoid any kind of subconscious prejudices on the side of the interviewers (you never know what kind of people are on the other side of the screen). And many more "tricks". I know that the core of the matter is to pass the challenges, but I do care about every single detail. I write down exactly how I'm gonna introduce myself, I prepare in advance potential questions like "tell me a project you've worked recently" to the point that I feel super confident talking about them. I don't leave anything to chance, but of course I may fuck it up sometimes (and I did 4 months ago in the systems design interview).
In any case, I could easily submit my cv dozens of times, but I find that preparing exhaustively for a couple of weeks for 1 or 2 jobs works best for me (based on previous experience. I have worked for around 5 companies so far in my entire career).
In my cv I care a lot about the details: the typeface, margins, grammar (I use llms since i’m not a native speaker), bullet point order, succinctness, etc. Perhaps that counts for something. Then if I get an interview, that’s like already 50% of the job done. Im an easy guy imho. I have failed mainly systems design interviews, so that’s where I put some work nowadays.