The biggest risk for an AI SaaS MVP is over-engineering: building a production-grade multi-tenant AI platform before you have 10 paying customers. The second biggest risk is under-engineering: building a prototype that cannot evolve into a product. The MVP architecture must be simple enough to build in 8-12 weeks but structured enough to evolve without a rewrite.
What to Build in the MVP
Build in the MVP: (1) Single-tenant architecture: one database, one model, one configuration. Multi-tenancy can come later. (2) One AI feature: the highest-value AI feature, implemented end-to-end. Do not build three mediocre features — build one excellent one. (3) Basic authentication: email/password or OAuth. RBAC can come later. (4) Simple billing: Stripe integration with one pricing tier. Usage-based pricing can come later. (5) Basic monitoring: logs and error tracking. Per-tenant metrics can come later.
What to Defer
Defer until you have product-market fit: (1) Multi-tenancy: start with single-tenant, add multi-tenancy when you need to serve multiple customers on shared infrastructure. (2) Per-tenant model routing: start with one model for all users, add routing when you need tiered pricing. (3) Advanced observability: start with logs and basic metrics, add per-tenant dashboards when you have paying customers. (4) RBAC: start with admin/user roles, add granular permissions when enterprise customers require it. (5) Edge inference: start with centralised inference, add edge when latency becomes a competitive issue.
Pro Tip
The MVP should be buildable in 8-12 weeks by a team of 2-3. If your MVP plan requires more than that, you are building too much.
The Evolution Path
Plan the evolution: MVP (single-tenant, one model, basic billing) → V1 (multi-tenant, per-tenant config, usage-based billing) → V2 (model routing, advanced observability, RBAC) → V3 (edge inference, multi-model, enterprise compliance). Each version adds complexity only when the business requires it. The key architectural decision at MVP: choose a stack that can evolve through these stages without a rewrite. Next.js + PostgreSQL + pgvector + a single LLM API is sufficient for MVP and can scale through all four stages.
Conclusion
The AI SaaS MVP should be simple: single-tenant, one AI feature, basic billing, basic monitoring. Defer multi-tenancy, model routing, and advanced observability until you have paying customers. Choose a stack that can evolve without a rewrite.
Key Takeaways
- MVP: single-tenant, one AI feature, basic auth, simple billing, basic monitoring
- Defer: multi-tenancy, model routing, advanced observability, RBAC, edge inference
- Build one excellent feature, not three mediocre ones
- The MVP should be buildable in 8-12 weeks by 2-3 engineers
- Choose a stack that evolves: Next.js + PostgreSQL + pgvector + single LLM API