Introduction Every development team has one, that critical application that runs the business, that nobody dares to touch, and that a brave team somewhere is slowly rewriting. In the meantime, the business doesn't stop. New requirements keep coming, and someone has to handle them.
Source: [Dev.to](https://dev.to/jeancy/how-to-plug-a-lambda-function-into-a-legacy-application-without-changing-a-single-line-of-code-4bcd)