I am an undergraduate CS student at a US college. Before this summer, I contacted a professor in Game Research and was offered the opportunity to work with one of his PhD students. Currently, I am focusing solely on this opportunity. I wrote lots of code and helped the PhD student run experiments and collect data.
The best outcome of this opportunity would be a publication and a recommendation letter. However, I am only 50% confident that I will be able to get one of the two at the end.
Are there other practical ways for me to demonstrate my contribution (that can help with future applications)?
Any other advice would help too.