You Never Know, by Calper and Simon Field; Used to Have it All, by Fais & Afrojack; Drifting Away, by Felix Cartal and Ofelia K (great beach music, by the way!); Starlight, by Jai Wolf and Lenno;
More thoughtfully, what sort of specific problems should one be able to solve in order to consider him or herself an expert? At least in Tech, the impostor syndrome haunts many people. I admit I got myself in this trap ever now and then. But today one thought came to mind, what make an expert?