When you are working on a project, if you hit the edge of your current knowledge / skills, push just a little bit further when it’s something that interests you instead of just aiming to hit the basic requirements / lean on other people.
This minor effort compounds over time; do it for twenty years and you’ll be an expert in multiple disciplines and also an expert in how to tie them all together into one cohesive whole. Aim to be a “T-shaped” person, and just expand over time.