Dynamic image resizing with Google Cloud Functions

For a small project I needed dynamic image resizing, meaning I would call an image in an url, append some parameters for resizing and return a smaller image, so something like example.com/image.jpg?w=50&h=50. Now there are several open source projects capable of doing that, most notably Thumbor. However, I wanted to try something new. I recently dabbled a little with Google Cloud Functions and it seemed like a good candidate. However, I feared the initial spin-up time of the functions might be problematic. »