What constitutes personal data?
The GDPR applies to ‘personal data’ meaning any information relating to an identifiable person who can be directly or indirectly identified in particular by reference to an identifier. This definition provides for a wide range of personal identifiers to constitute personal data, including name, identification number, location data or online identifier, reflecting changes in technology and the way organisations collect information about people.
What should you do as Dev?
Ask you self what you data will you store and is it really necessary. If you must store personal data add functions to read this data to send it to a customer (identifiable person) and also a function to remove a data for a customer. If yous tore personal data think also about encoding of the data.
Trade consciously with the data of the customers, the visitors and think about read, remove and encoding. I mean this should think in the right direction to get a solid plugin in the topic of GDPR.