You would already be aware that there are multiple options given by Google Cloud Platform to store data. Here is Google documentation on when to use which option:
Google recommends using Google Cloud Storage (GCS) to store static content like files/videos etc. There is something called 'Blobstore' as well which is also used to store such content but it is on the way to being deprecated. This page talks about using GCS to store images.
Look at this page to understand basic requirements for setup of GCS. In the Cloud Store Browser below following buckets are already available. If you select any bucket, you would be able to see the objects created in it.
Here you can see the image file in the 'jda-pd-slo-sandbox.appspot.com' bucket. You won't be able to add/delete files or folder from the browser if you don't have proper access but through code (running with the service account) it should not be a problem.
Objects on GCS are immutable so you can't edit an ob…