Product Context
AdPilot is a SaaS marketing platform for small and medium-sized businesses (SMBs). Its home dashboard recommends campaigns, audience segments, budget actions, and product tips; the challenge is launching personalization for a newly onboarded SMB segment with little or no historical interaction data.
Scale
| Signal | Value |
|---|
| DAU | 6M businesses/users |
| New SMB accounts/day | 120K |
| Peak recommendation QPS | 45K |
| Recommendable actions/content | 2.5M items |
| New items/day | 80K |
| p99 latency budget | 180ms end-to-end |
| New cold-start segment | ~18% of new signups |
The new segment has sparse behavior, limited CRM integrations at signup, and different business profiles from existing customers. You need to design an end-to-end ML system that serves useful recommendations on day 0, improves quickly as signals arrive, and avoids overfitting to larger enterprise segments.
Deliverables
- Clarify the product objective, success metrics, and what “personalization” means for a new SMB with no history.
- Design a multi-stage recommendation system (retrieval → ranking → re-ranking) that handles zero-shot and sparse-signal cases.
- Define the offline and online data pipelines, including feature generation, labels, training cadence, and how to prevent training-serving skew.
- Specify the serving architecture, latency budget by stage, fallback behavior, and capacity planning at peak QPS.
- Propose an evaluation plan covering offline metrics, online experiments, segment-level analysis, and long-term monitoring.
- Identify major failure modes for the new SMB segment, including feature drift, segment misclassification, and poor exploration.
Constraints
- Day-0 recommendations must work even if the business has only signup metadata (industry, region, company size, acquisition channel).
- Some integrations (payments, CRM, ads) arrive hours or days later, so feature availability is uneven.
- Cost target: serving compute under $0.0015 per request.
- Compliance: no use of sensitive attributes; all features must be auditable.
- Freshness: new campaigns and recommendations should be eligible within 15 minutes of creation.