Not the parent poster but:
> how are you structuring data such that it is available to you and your site, without also being able to pull it all out into an archive?
I don't believe the point is that it cannot be pulled into an archive, but that collecting all the data that belongs in such an archive of an specific user (and that user alone) can easily be a very complex task for projects of certain size:available manpower ratio, to the point that showing a query to a relational database with a well defined schema as an example strikes me either as ignorance of the state of real world software development or a gargantuan middle finger.
> literally all of my experience has been that securing data is a much harder challenge than any other part of a web facing system.
Depending on the project that can easily be the case. There's of course the fact that no one can really claim all their stored data is safe from malicious actors, just reasonably secure according to their knowledge and what they're aware their software does; so comparing its difficulty to other things seems overly simplistic.
And sure, there's a lot of things that will be harder than an archival feature regardless of the data storage mess a project may be in, but it does not diminish the work required to implement archival on many of those.
> Also, the thing that everyone seems he’ll bent on ignoring: you do not need an archive mechanism if you do not store data
Congratulations if you happened to store absolutely no PII when building your product. You not only have the luxury of being able to provide any value at all without data, you happened to not store things that a lot of people often don't consider PII but that the GDPR does such as IP addresses.
> And given we’ve known gdpr has been coming for at least a year - aside from companies that tried to bribe it away I guess - new projects should have there data set up so that archiving isn’t a monumentally challenging task.
Can we really pretend with a straight face that the overwhelmingly massive cost of changing legacy software can be handwaved away and that all new projects are developed by people that not only are aware of the GDPR (that's an absurdly minuscule amount of all software developers) but that they are competent enough to fully comply with everything in it? I've worked on HIPAA-compliant software, I've seen people that have been working for years in the industry (both health and software) screwing up and/or making extremely close calls. This is not "escape user input in SQL calls", this is a sizeable piece of regulation without a clear course of action for compliance that will fall on the laps of developers of all skills around the world.