Development on a Platform: How to Achieve Efficiency

A popular method in enterprise development - create multiple solutions on a common platform or core. This way is chosen by many development companies, and now it is done in-house in banks and corporations. While the platform is expected to ensure the effectiveness of solutions, experience shows that the platform team becomes an "internal vendor," interactions with which slow down development and limit solutions. I'll share my experience creating and developing on platforms. What should be included in a platform, and how can effective extension points be created? How can effective collaboration between the platform team and those developing on it be organized?