Your field data, that is, the actual values you entered into the field for any product or other content, is stored in Shopify along with all of your other data. Specifically, the data is stored in Metafields, using a namespace particular to Custom Fields (metafields.custom_fields.YOURNAMESPACE). When you see your data in the app's interface, it was pulled in real-time from Shopify and filled into the form.
Your field definitions are stored in the app's database. Definitions are just your settings for the field, like if it's an HTML field and what you called it. The app uses these definitions to create the forms you use in the app, like the dropdowns or WYSIWYG fields.
If, for any reason, the Custom Fields app "goes down" your data will not be lost and your customers and visitors will not be impacted.
We do not store your field values in our database. This means that the values you enter into this app are available outside of the app, if you need them and have your own developers, using the Metafields API. This also means that any questions regarding the privacy of the data you enter should be directed at Shopify. This app only handles the data "in transit".
If you use our export tool, we collect the information you've requested by asking Shopify to provide it back to us via the Metafields API in near real-time. The information we get back is temporarily cached to build the file. We then store that export file on our host. If you have questions regarding our host's privacy policies, please visit https://pantheon.io and also https://pantheon.io/blog/announcing-privacy-shield-framework-compliance
If you use our import tool, we do not permanently store your file. We parse the file and cache the data temporarily. Garbage collection on our system deletes your upload file within a few hours.
Images and files added through this app are stored in 3 possible ways:
1. Our legacy file system stored and served files from our Amazon S3 bucket specific to this app. Amazon's S3 system is highly reliable and is widely used by enterprises. Most customers have been migrated away from this system.
2. Our current file storage mechanism places files into a special theme in Shopify that identifies itself as our asset theme. This comes with the benefit of full access to your files at any time, and makes all of Shopify's image filters available for developers.
3. Merchants using our Plus plan have the ability to set up their own Amazon S3 account and use their own Cloudfront CDN if desired.
Our app is GDPR Compliant. You can learn more by reviewing our Terms of Service