Original founders of the agency. Often involved in finances, operations, people.
UX research, interaction design, graphics.
Writing code, building systems.
Helping with direction, ongoing improvement of assets.
Keeping client work on track, and often double as product manager.
Helping to bring in new business and ensuring ongoing services are going well, sometimes steps in as a project manager.
Digital marketing specialist
Those fluent with search engines and social media. Post, manage, and report on performance. SEO, SEM, PPC usually fall in this bucket as does inbound marketing like landing pages and email.
Those who can write beautifully and attract new users and customers for your clients.