The majority of my software development career I've focused on backend development, naturally I'm more comfortable there. However as I've started working on my product I've realized that designing the schema, data models, and API first isn't the most efficient use of my time because things change dramatically as I build out the frontend and discover my assumptions were wrong.
I did some research and came across this video on YouTube: https://www.youtube.com/watch?v=whEE7WPdj-A
His recommendation is to begin with the frontend and figure out the user flow, then once that's understood you can start working on the backend. It seems to make a lot more sense so that way you have an idea of what you need before you build it given you're starting with what your end user sees.
Sharing my experience and looking to hear others!