Ridiculous. You must be talking about learning only the syntax of a new language. Truly internalizing how to wield a new language will take months to years. A

Ridiculous. You must be talking about learning only the syntax of a new language. Truly internalizing how to wield a new language will take months to years. A dev that switched from language X to Y "in a few days" will just write X using Y syntax. Here's a good example of going from Java to Python: https://youtu.be/wf-BqAjZb8M?t=1327 https://youtu.be/wf-BqAjZb8M?t=1327.