We have a bunch of MIT students. The sad truth is that everyone is scared of technical interviews.
While there's definitely good people at non-elite universities, selection bias is at play here too.
For example, in the senior year case, you're just looking at people who were concerned enough about interviews to go to interviewing.io during their senior year. Most people I knew at MIT had a full time offer they were happy with from their Junior year internship by their senior year.
You can actually see the impact of this in your graphs too, notice that the % of people with a 1 or a 2 in elite schools increases for senior year vs junior year. People who have been doing well in technical interviews and have good return offers won't spend as much time preparing.
The hell? What sort of problems are you getting?
Were you doing edit distance and word break and shortest palindrome in middle school?
* Print pascal's triangle up to the n-th level, with proper spacing (so that it looks like a triangle).
* Make the game Go for 2 players. I got a sub problem of this during my Google interview (determine whether a piece is captured).
the rest was more regular (I didn't apply to super elite jobs, and both the companies with these two hard tests failed, so it's no indication neither about them, neither about me)
How long were these interviews? Seems like something I could do in a few days not a 2-hour interview!
And, please, when showing graphs for comparison purposes: make the Y axis scale identical, or the results are quite visually misleading.