I still enjoy thinking about ideas in mathematical biology - there is huge scope for the application of very intriguing math! For ex., check out these papers (by other people!) on trajectory inference from scRNA data analysis, or the categorical-inspired UMAP algorithm. I also made this colony-growth simulation for a biophysics class in my senior year.
Here are some fun math simulations that I made.
Here is a presentation detailing our findings on the frog model paper. Check out the animations on slide 7 to see the frog model in action!