How would you scale AI systems from 10k to 10M users?
### Signal to interviewer
I can scale AI platforms with phased architecture and operational discipline instead of reactive firefighting.
### Clarify
I would clarify growth forecast, regional mix, workload complexity, and non-functional SLO requirements.
### Approach
Use a stage-gate blueprint: capacity milestones, reliability controls, cost optimization checkpoints, and support scalability planning.
### Metrics & instrumentation
Primary metric: successful request volume at SLO during peak conditions. Secondary metrics: autoscale efficiency, support-to-user ratio, and onboarding throughput quality. Guardrails: cost blowout, severe incident frequency, and latency degradation under burst.
### Tradeoffs
Early heavy investment improves resilience but can slow feature delivery. Lean infrastructure accelerates growth but risks instability at inflection points.
### Risks & mitigations
Risk: sudden traffic spikes overwhelm services; mitigate with queue buffering and admission control. Risk: rising unit economics; mitigate with route optimization. Risk: support bottlenecks; mitigate with in-product recovery and tooling.
### Example
A consumer writing app scales by splitting free versus paid traffic classes, adding regional replicas, and introducing adaptive model routing as demand grows.
### 90-second version
Scale AI systems with stage-gated infrastructure and product operations. Align each growth step with SLO, cost, and incident controls so expansion remains stable and sustainable.
- Which SLO must remain stable as user count scales most aggressively?
- What growth milestone should trigger the next infrastructure stage?
- How would you design traffic segmentation for paid versus free users?
- What forecasting and load-testing loop supports proactive capacity planning?