SAAS Functionality Review

I need a comprehensive review of my SAAS platform's deliverables, focusing on functionality, particularly around user access control. I need assistance with authentication. Not looking to critique the build, just make sure all deliverables are there(API's, Keys, database details, build instrux etc..). I also would like to see if/when it is delivered how to set up a repository storage/access for future work. These are immediate needs, the ability to help afterwards with small scale UX/other platform improvements(from payments to route optimization) and continuing advisory services is preferred/welcomed with priority.

Key Tasks:
- Review current authentication methods
- Identify and address functionality gaps
- Recommend improvements and organize next steps

Ideal Skills:
- Experience with SAAS platforms
- Strong background in user access control
- Expertise in authentication processes

Looking for a detailed, organized approach to ensure a robust user access control system.