Project idea to showcase my skills

I've been working as software engineer for 1 year now, and I worked mostly using python and rarely using cpp.
I'm not that proficient in cpp but I'd like to improve my skills and work on a personal project to advertise my skills ( I'm thinking about looking for another job ).
Are there any project ideas that could help me learn and showcase my skills ? it doesn't have to be something innovative or unparticular
for reference I work in automotive industry, but I don't mind switching.

https://redd.it/1pci2m2
@r_cpp