[Tmp1234]

It seems we both agree, indirectly, that these interview tests are like IQ tests. You are comparing them to the SATs and the SATs are just wrapped up IQ tests like the tech interview. Studies have shown scores on the SAT don't increase by more than 100 points or so even with 100s of hours of practice. In the end, the algorithmic thinking you mention just seems like another way of saying intelligence which would be a factor in any subfield I enter.

And the truth is I've been doing interview prep on and off for at least a year and I'm still at this stage. My goal is to be good enough to get into a Big 4. If I can't do that, I don't want to continue. Given that, do you think I should quit?

[blacksoil]

Honestly, I feel like your motivation is wrong. Most of the most amazing programmers are those that are genuinely interested in particular topics, worked hard in the area, and finally became very good at it. Your mindset really shouldn't be going to big 4 because they're cool or sound prestigious. I don't believe such mindset will last long there anyway...

Aside from personal opinion above, the chance of getting to Google is less than the chance of getting accepted to Harvard. And as you probably know, there are people who are qualified who got turned down by Harvard because they don't have enpugh spots anyway. So if your goal is merely to get there, statistically speaking there are much more plausible things to aim for, so you shouldn't waste your time..