Question: I'm looking for a platform that simplifies building multi-tenant SaaS applications with robust data models and secure authentication.

If you're looking for a platform to make it easier to build multi-tenant SaaS apps with a rich data model and secure authentication, Supabase is a good option. It's an open-source Firebase alternative that includes a Postgres database, Row Level Security for user authentication, and a built-in user management system. The service also supports frameworks like Next.js, Svelte and Flutter, and includes features like edge functions, real-time data synchronization and vector embeddings for machine learning integration. Supabase's pricing includes a free tier with unlimited API requests and various Pro, Team and Enterprise plans for different needs.

Another good option is ROQ, which offers a broad set of tools for building multi-tenant, multi-role SaaS apps. It includes secure database query, authentication and authorization support, including social logins and 2-factor authentication. ROQ also offers managed Postgres database deployment, multi-tenancy, role-based access control and Stripe integration for payments and subscriptions. Its AI-assisted data modeling and visual review features can help speed up development and deployment of complex data models.

For a full-stack backend option, Rocketgraph is a powerful service with a PostgreSQL database, strong authentication and support for GraphQL. It includes a complete backend setup with Hasura console, serverless functions and a relatively easy-to-use front-end agnostic JavaScript API. Rocketgraph also integrates with AI services like chatbots and offers fine-grained authorization rules, making it a good option for building production-grade web apps quickly. Its Developer plan comes with 20GB PostgreSQL DB and premium support, which should be enough for teams with a lot of users.

Also worth a look is Backendless, a low-code app builder that can handle responsive apps for the web and mobile devices with a visual UI builder and codeless logic for frontend development. It includes a real-time database, a visual schema modeler, streamlined user management and a range of third-party authentication providers. Backendless also supports flexible deployment options like serverless and self-hosted infrastructure, so it's a good option for developers who want to build and run high-performance apps efficiently.