You DB design is most important.
I'm a coder, and I prefer code, but ... if you screw up the DB design, your code will be a nightmare. Your code won't have a chance!
Even when you try to refactor the DB design, you will have so much work around code, that fixing it all will be overwhelming.
This isn't a preference or even a close one, it's very much leaning toward the DB design being most important.
EDIT: Even if you were to have key-value pair tables where everything got dumped into it, that would still be a DB design based on business requirements.
