While many teams can be quite lean, where you have just a developer and a designer, two other roles are commonplace in large teams.

• Product owner (PO). Amongst other things, they manage the backlog and create user stories for the dev team. On distributed teams, a business analyst may play a product owner proxy.

• Tester. These are engineers who focus on validating that a user story satisfies all acceptance tests, is bug free and doesn’t cause any regression defects in the product. They’re responsible for the quality of the application, so some teams also refer to them as quality assurance analysts or QAs.

Many teams also designate a lead developer, also known as a technical lead (TL). This role provides design oversight and handles the quality of the technical solution. People in this role may coach other developers in a first-amongst-equals capacity. In some organisations, they’re also responsible for code reviews. Between the PO, tech lead and tester, you have representation for the three amigos of agile software development.