Is it cheating if I develop some part of my MSc. thesis in a hackathon in a team? I am working on my master thesis in software engineering. I am going to present the idea of my thesis in a hackathon (startup competition), so most probably, we will make a team and develop a minimum viable product based on my thesis.

The question is:

Can I mention to this minimum viable product as the validation of my thesis?
Or it would be considering as plagiarism since i have not developed it alone, but in a team.
I believe it would be fine and acceptable as long as in your thesis writing you name who helped you and how they helped you.

I doubt anyone will think less of your thesis for having people help you. As long as it is still clear that you did a lot of work yourself... this team isn't completely doing your project and thesis for you!

You could ask your thesis advisor to be certain.

Many PhD students hire research assistants to help them code software engineering projects.