Build Enterprise CRM SaaS Platform

I am launching a cloud-based CRM tailored for enterprise-level companies and I need it built from the ground up as a true multi-tenant SaaS. The first release has to handle thousands of concurrent users, integrate easily with single sign-on providers, and expose a clean REST/GraphQL API so larger organisations can plug it into their existing data pipelines.

At launch the system must deliver:

• Lead management – capture, score, segment, and assign leads in real time, with role-based dashboards.
• Customer support ticketing – omnichannel intake, SLA tracking, and an internal notes stream that sits next to each ticket.

Everything—from database schema to front-end interactions—should be engineered for extensibility because additional modules (for example, email marketing automation) will follow soon after MVP.

Please outline in your proposal:

• Technology stack you recommend for a scalable, multi-tenant environment.
• Approach to security, data isolation, and GDPR compliance.
• Milestone plan covering architecture, feature build-out, testing, and deployment to my chosen cloud provider (AWS, GCP, or Azure—open to your suggestion).
• What you will deliver at each stage: source code, infrastructure as code, API documentation, and a short hand-over session.

Clean, well-commented code, automated tests, and CI/CD pipelines are non-negotiable acceptance criteria. Looking forward to seeing how you would bring this enterprise CRM SaaS to life.