Diana,

These terms all refer to IT professions and in the U.S. at least the use of the word architect has become popular for creating new job titles (we like our job titles in the U.S.!)

I don't think you're going to want to do a literal translation of architect, so I would suggest either programmatore o sviluppatore here.

Here are some definitions I was able to find on each of the different types:

information architect
The term information architecture describes a specialized skill set which relates to the management of information and employment of informational tools. It has a significant degree of association with the library sciences. Many library schools now teach information architecture.

application architect
Typically, the architect is in charge of determining how to partition an application to best take advantage of the available resources and technology and meet the requirements of the application.

data architect
Since the data architect is the end-users’ interface and translator of their business requirements to the IT community, the architect must possess good interpersonal skills. A data architect must have the ability to facilitate agreements and resolve conflicts amongst organizations. To do that successfully, an architect must be able to interpret business needs into data requirements – including such attributes as naming standards, consistent data definitions, data aliases, associated business rules, data sources, retention criteria, derivations, security restrictions, accessibility, reusability, currency, frequency of update, linkages, and integration. (See the chart for a sample outline of roles and responsibilities.)

.NET architect
The .NET Enterprise Template Series covers the fundamental concepts of Enterprise Architecture, Distributed Application Architecture, and Enterprise Template design, development, and deployment. A thorough examination of these disciplines is too expansive to be adequately covered in a single article; however, you will, at a minimum, examine the major conceptual foundations of each discipline. A brief introduction to Enterprise Architecture and Distributed Application Architecture will aid your understanding of the role of Enterprise Templates in a large, distributed organization. To create Enterprise Templates, you must have either Visual Studio .NET Enterprise Developer or Visual Studio .NET Enterprise Architect installed on your computer.