Phone screen with HR, followed by a tech screen on an online coding platform.

The tech screen went very well. I was able to solve the problem of making change given certain denominations of coins, as well as write out working code for the vending machine itself (efficient storing of items, vending the items, etc.).

The issue came when I got the call from the recruiter saying that the position was for an "L6/7 Principal Engineer" and they felt that I did not do well enough on the coding exercise, as there were "unaccounted for edge cases". Not sure what edge cases they were referring to, as there were no tests given for me to run. Every test that I went through with the interviewer passed just fine. Really disappointing and confusing feedback, as the code worked well by the interviewer's own admission.

If the position was for a Principal Engineer, I'm not sure why the job description lists "Senior". There is clearly a difference between the two. Knowing that, I would have also asked for more money coming into the process.

Vending machine OOP, change making algorithm.