Multi-tenant SaaS authorization and API access control - Java Proof Of Concept

I'm looking for a seasoned developer with extensive experience working with Multi-tenant SaaS applications, specifically focusing on access control.

Key objectives:
1. Primary Focus: Design and implement a robust access control system for my Multi-tenant SaaS application.
2. Specific Functionality: The access control should proficiently handle role-based access to ensure users are efficiently funneled to their respective roles within the application.
3. Timeline: I need the project to be completed ASAP. Therefore, candidates who can dedicate significant attention to this project right away are preferred.

Ideal skills and experience:
- Must have solid experience in building access control within Multi-tenant SaaS applications.
- Expertise in role-based access control development is paramount.
- Proven ability to deliver quality work under tight deadlines.

Note : I need below IDEA should be implement in Java Micro Service as POC Project
https://docs.aws.amazon.com/prescriptive-guidance/latest/saas-multitenant-api-access-authorization/welcome.html