Because this is your first full time professional position, I'm inclined to accept that some of the criticisms are genuine and you have a growth opportunity to

Because this is your first full time professional position, I'm inclined to accept that some of the criticisms are genuine and you have a growth opportunity to learn from them. BUT The part that bothers me, as someone who has been in this industry for almost 25 years and leads teams, is that your manager was not in that meeting with you. That I find absolutely unacceptable. Your manager is not just the person you report to. They are also responsible for your success and they should be your advocate. This type of feedback should be coming from them, not the higher-ups. The higher-ups should look to your manager to manage, and your manager should look to you to accomplish your duties. The higher-ups should not have enough insight into the day to day minutia of your project to know to point the finger at you. They should get status reports from the project manager and if things aren't going smoothly they will ask why, but a good PM will point the finger at themselves and protect their team. And if there is a problem with an individual team member they will address that one on one in private before escalating. If that feedback is not addressed then the project manager may escalate to your direct manager/boss who is then responsible to work with you more. Again, one on one in private. If, after all of that ... things still aren't improving, then it can be escalated to HR and they can take additional action. But unless you are leading a project, you are not accountable for the success of that project as a whole and - I'm going to sound like a broken record here but - any direct feedback pertaining to you individually should come from the project manager or your direct manager. Under no circumstances should you have been in a meeting with your boss's boss to discuss your performance without your direct boss being present. The thing that would be troubling me the most, if I were you, is the question: "Why did this happen? Why are you on your boss's boss' radar at all?" The implication of that question really bothers me. It implies that your manager(s) might have thrown you under the bus to cover their own ass. Absolutely evaluate the feedback and see if you can grow from it. But I would have a conversation with your boss and basically call them out for not being there to advocate for you. And ask them how such an inappropriate meeting was allowed to transpire in the first place. You deserve answers.