Earlier quoted context omitted.
I question yahoo's engineering chops 4 out of 5 times after interviewing hotshots from search, ads, or research. After interviewing dozens of folks from yahoo, I've pained the following picture about the engineering there - the vast majority of it is stuck in 1995, some bits of it have evolved isolated from the rest of the tech world - it's steam punk, then there are a few parts that are shiny and new but skin deep.…
I'm wondering if you are the victim of sample bias - The Yahoo employees that are happy and talented are likely well paid, well rewarded, and won't be interviewing with you. You are possibly talking to the ones who either are less talented, or unhappy and are reflecting their perspective to you.
Nearly no one I've interviewed from yahoo has bad-mouthed their former employer, so my negative bias is from working with people that have passed the technical interview and have been hired... the quirks that people pick up after working at yahoo for many years are odd to me (like the strange desire to put squid in front of everything).