I've been both a database architect and a database designer.
The one pertains to tbe overall structure of the database
system, not only in relation to the information it is going to store but also in terms of its relationships with the user, the computer system it runs on and other database systems with which it has to interact. The other, design, is determining what data gets stored where and the relationships between the data items which are being stored.
However, I loathe and detest the use of the verbified form "to architect". I can see no new meaning or nuances of existing meaning which can justify using it instead of designed, in exactly the same way that you would discuss the work of the architect of a house.
Jargon is useful in its place, but this is one term which belongs in the nether depths (with MacDonalds burgers).
