>I'm sure Google is able to adopt a working ticketing system. If you already have an issue tracker then it makes absolutely no sense to keep a separate out-of-band ticketing repository such as source code sprinkled with TODO entries.
If I'm on another team looking at using your code for whatever reason, I may not be familiar with your ticketing system, what is where, how it's organized and prioritized, etc. I appreciate an indication in the code that that function or class might have some significant areas for improvement. If it's relevant enough to what I'm doing, maybe I'll handle the TODO and open up a code review for your team. Ideally you've got a TODO with some details and also a ticket I can reference to see what's going on with it or what discussion has already occurred around it.
But companies of FAANG size often have so many different developers on totally different teams that they're probably not going to have the time or inclination to go look through your ticket backlog. Having any deficiencies or areas for improvement clearly marked in the code is a benefit in those situations.
If I'm on another team looking at using your code for whatever reason, I may not be familiar with your ticketing system, what is where, how it's organized and prioritized, etc. I appreciate an indication in the code that that function or class might have some significant areas for improvement. If it's relevant enough to what I'm doing, maybe I'll handle the TODO and open up a code review for your team. Ideally you've got a TODO with some details and also a ticket I can reference to see what's going on with it or what discussion has already occurred around it.
But companies of FAANG size often have so many different developers on totally different teams that they're probably not going to have the time or inclination to go look through your ticket backlog. Having any deficiencies or areas for improvement clearly marked in the code is a benefit in those situations.