As you prepare for your viva think about a Situation where you did something well. What was the Task that you were trying to accomplish? Was there a goal you were aiming for or a problem that needed a solution?
Whatever the circumstances, what Activities were you engaged with? And when you had finished what were the Results of your work?
Reflecting on a story where you describe the Situation, Task, Activities and Results helps to create a useful narrative for exploring your capability with others. It can be a big help for job applications, interviews or pitching yourself.
Reflecting on a STAR can also help a lot with building confidence. It’s a foundation of knowing that you are good enough.
And you aren’t limited to one story. Find as many as you can and build a constellation of stories that you can look at when needed, to show yourself that you are good.