Agile team roles and responsibilities

Agile team roles and responsibilities
scrum

Agile and Scrum team roles

There are should be only three SCRUM roles:

The development team can be sub-divided into business analysts, UI and UX designers, developers, testers, and system architects. If appropriate, this team might extend invitations to content writers, marketing, PR and release managers, who need to align their work with the release schedule of the product.

A development team should collectively have the skills necessary to produce good quality software within the sprint. 

This cross-functional group can become large and difficult to manage so Agile recommends your core development team should be around 5-9 people, the Product Owner and the Scrum Master are excluded from that number. This optimal team number is supported by operational management research on team dynamics which highlights the exponential communication issues which occur when too many people are involved.

https://dzone.com/articles/applying-brooks-law-to-lines-of-communication-and
https://www.teamgantt.com/blog/what-is-the-ideal-team-size-to-maximize-productivity

So, in conclusion, try to keep your core development teams within the recommended range of 5-9 people.

Additionally, there are other key stakeholders who will contribute to the creation of the product including your Business Owners, Project Sponsor, Stakeholders, BAU, Customer Support, Marketing, Data Scientists and Sales.