How to share code between functions

There are some codes, like setting headers and other utils I want to share between functions. Having them in a utils folder at the root of my project is not working, since only the function's path is deployed. Any ideas how I can reuse some utils?

TL;DR

One way to share code between functions is to create a separate folder for the common code and use symlinks. You can create a symlink in each function's folder that points to the common code folder. This way, the functions can access and reuse the shared code.