Multi Tenant AI SaaS Architecture on AWS and MongoDB (A Practical Guide)

Key Takeaways

• Multi tenant AI SaaS is mostly security and ops.
• Start with shared collections plus strict tenant filtering.
• Store binaries in S3, store metadata and workflow state in MongoDB.
• Use managed identity and least privilege IAM.

If you are turning an AI workflow into a SaaS product, the hardest parts are usually tenancy, security, and operations. This post outlines a practical multi tenant architecture for AI enabled apps built on AWS with MongoDB.

Tenancy models

Common models:

• Database per tenant
• Collection per tenant
• Shared collections with tenant field

In practice, most teams start with shared collections plus strong tenant filtering, then move up the isolation ladder for high compliance customers.

MongoDB reference:

• Multi tenant considerations: https://www.mongodb.com/blog/post/building-multi-tenant-applications-with-mongodb

Key AWS building blocks

• Identity: Amazon Cognito
• API: API Gateway plus Lambda or container services
• Storage: S3 with tenant scoped prefixes
• Networking: VPC, private subnets, and private endpoints

References:

• Amazon Cognito: https://docs.aws.amazon.com/cognito/latest/developerguide/what-is-amazon-cognito.html
• API Gateway: https://docs.aws.amazon.com/apigateway/latest/developerguide/welcome.html

Data isolation and access control

Rules:

• Enforce tenant ID in every query server side
• Use row level authorization checks
• Use least privilege IAM roles

Security references:

• AWS IAM best practices: https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html
• OWASP Top 10: https://owasp.org/www-project-top-ten/

Workflow state and jobs

AI systems need durable job state:

• queued, running, needs review, complete, failed

MongoDB is a good fit for this state plus metadata. For compute, you can use:

• Step Functions for orchestration
• SQS for work queues

References:

• Amazon SQS: https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/welcome.html
• Step Functions: https://docs.aws.amazon.com/step-functions/latest/dg/welcome.html

zion services overview: https://lidvizion.ai/

FAQs

Q: Do we need separate databases for every tenant? Not always. Separate databases increase isolation but also increase operational cost. Choose based on compliance requirements.

Q: How do we handle per tenant rate limits? Implement throttling at the API layer and enforce quotas in your job scheduler.

Q: How do we onboard enterprise customers with stricter requirements? Offer a higher isolation tier, for example dedicated database and private networking.

Internal reference:

• Lid Vi

Q: What should we link to internally? A: Link to relevant solution pages like Computer Vision or Document Intelligence, and only link to published blog URLs on the main domain. Avoid staging links.