Personal brand of a programmer

Many people working in IT, when they hear the phrase "personal brand", imagine celebrities who are famous for being famous, internet gurus for all sorts of things, or coaches who tell us that we are winners. It's time to change that perception! A strong personal brand of a programmer can be used to increase the influence on the company/project, improve the position on the market or earn money from your knowledge. The only question is how to build it?