FWIW, when you see a username next to TODO() or NOTE() in Google-developed code, it's not the assignee, it's the author of the TODO comment. The idea is that every TODO should have a person you can check with to see what the history behind that TODO is and whether it's still relevant. The assignee is often whoever wants to work on cleaning up the code - it's intentionally left unspecified so that a.) people don't feel guilty or overwhelmed about leaving TODOs b.) the work can be load-balanced among different engineers at a later date and c.) the comments are (semi-)robust against people leaving the project.