It was when my engineering big boss asked my friend, instead of me, questions about a feature I was working on. And whenever I tried to jump into their conversation, he would turn his head to my friend and continue talking to my friend, as if I was not there.

Sounds simple, right? But at that time my impostor syndrome was at its worst point, which led me to take it that he didn't trust my capabilities to develop that feature. After that, overthinking played its part, telling me that I can't be a good developer, and I should quit and switch career path.

Eventually I decided to stay for a few months and see how things would work out. Things slowly went better, and I have successfully recovered my confidence ever since :)