I think it depends on the size of the company. The larger the larger the company, the more likely they are to split this stuff out. Though various titles may seem to bleed together. I have a software engineer title, while another guy on my team is a software architect… we effectively do the same job. Stepping back from a higher level view, as a general theme, those with an architect title are more likely to be responsible for an overall design, while the engineers may have some input and build things to support the design.

The quality of said designs can vary wildly. Some designs I get from other team I completely ignore, because they have no idea what they’re talking about. Just because someone has the title doesn’t mean they deserve it.