Which cloud storage with automatic thumbnail generation should I choose?

Question

Image processing

There is a task to store pictures of users and prepare miniatures from them.
Now the user is uploading a picture, it is immediately uploaded to S3 and is available via the link. Next, a task is created to create a thumbnail, the consumer takes the task and prepares the thumbnail, then the thumbnail is uploaded to S3. The problem is that, according to the business logic, access to the thumbnail is needed earlier than to the original. All these actions are performed on some backend.
I want to remove this backend from the food chain, and that everything would be done on the cloud storage side without my participation.
Who knows what kind of services?
There are options to use blanks for "layers", such as:
Amazon Lambda or Google Object Change Notification , or do something of your own based onAmazon S3 Event Notifications .
But I wouldn't want to bother with it.
Here is what I managed to google:
imgix.com
cloudinary.com
but perhaps someone else can advise something.