To effectively manage the development and implementation of an external account deletion process for a mobile app, as required by Google Play's new policies, you'll need a multidisciplinary team. Here's a breakdown of the key roles and expertise required:

Project Manager

2. Web Developer(s)

3. App Developer(s)

4. UX/UI Designer

5. Security Specialist

6. Quality Assurance (QA) Tester

7. Legal Advisor/Compliance Officer