Like others have said, it's not you. If you where in a position to derail a release twice, someone (not you) is not doing their job. You mentioned working on

Like others have said, it's not you. If you where in a position to derail a release twice, someone (not you) is not doing their job. You mentioned working on new features by yourself. That's fucked up. Junior devs can work on new things, sure but they need to have a senior guide. And the resposibility of the feature should be on the *senior* dev. In my opinion the best way to use a junior dev if resources to hold their hand are missing is to have them work on fixing bugs and support tickets for a while. This will give them a solid understanding of the code base and most external dependencies. Working on new features after that is way easier.