How do great design teams distribute responsibility, given that designers have different strengths (interaction, visual)?

I am a Product Design Lead at Rackspace. Our team has as diverse skill set and we've come to embrace this. One team with one backlog (4-8 members) T-shaped designers: one speciality, but solid base of capability Self-governing: the team divides work, breaks it down, decides amongst their strengths and interests Paired design when needed Pixar-style daily pin-up: design studio approach where we share WIPs every-single-day. Promotes help, humility, and iteration. As the team becomes closer, they work as a unit to GTD. Each member gives and receives mentorship. Specialists wishing to specialize are permitted to do so as long as the team GTDs. That said, we have well rounded designers. If you have someone who's lacking some base design capabilities, this highly collaborative approach can backfire.

In my opinion, (ideally in a smaller settings) an interaction designer and a visual designer should work like an art director work with a copywriter in the advertising world. They have to work together and influence each other simultaneously. During the process, they have to trust and acknowledging other's strengths, role and responsibilities. Let the interactive designer call the final shots for all the interactive design because it's what they are good at and vice versa. And what ever the interaction design lacks at, the visual design should help solve the problem and vice versa. For example, on a print ad, if the art work already tells the story enough, the copy don't have to work as hard to tell the story, it just need to finish the loop.  It's the same with interactive work. If the interaction design is brilliant, the visual don't have to work hard to help the process of interaction and can be more purely visual. So depends on the goal/strategy of the work, and what ever they came up with during the creative process, they need to adjust their designs simultaneously. In some companies, they polarize these two roles for the sake of production schedule/ more control in project management, or because they are a big company, which I personally think will/ may sacrifice creativity.

I agree with Ryan and Jacob's perspectives. I'd also add that career growth has a place too. Where do team members want to grow? Maybe you have a unicorn on staff and just don't know it because they haven't been fully developed.

I don't think there's an easy answer to this, or a template to follow (not helpful, I know ;). You're on the right track in seeking a pair approach, and that pair may have skills that bleed over into tech or strategy too, not just covering the design spectrum. The key to getting the best from your teams is knowing their individual superpowers and kryptonite, and creating teams with complementary skillsets. The umbrella of design is pretty vast at this point, and I'm finding it ever harder to cordon off a subsection of those skills to a specific type of designer. And the schools aren't teaching that way anyway. At Hot we use a skills assessment to understand more deeply where everyone has experience and interest. Also key to success: communication. When I hear that people are unclear about their role and responsibilities on a project, to me that points to a lack of communication. When team roles and job descriptions are more fluid, communication has to take up the slack to align workstyles, deliverables and expectations.