I worked for AOL, who Verizon recently merged with Yahoo . It was inevitable they destroyed the startups . Yahoo processes made us look lean in comparison, and we were another old web 1.0 company . The first thing they make you do is port to their tech stack and so much time is spent on that process and approvals from central teams that it's a wonder anything gets done . They've got their own package manager, own internal ec2 clone, own build system, own Linux distro, own deploy system, and if any of those things were good it might make sense, but they're mid-2000s tech in quality .
Flickr disappeared for a crucial year post merger, and apparently they were porting to Yahoo's internal account system: https://gizmodo.com/5910223/how-yahoo-killed-flickr-and-lost... . At least that produced some user facing unification compared to some of the tasks we had . The attitude has not improved since .