How would you target promotions to grow consumers?
Company: DoorDash
Role: Machine Learning Engineer
Category: Machine Learning
Difficulty: medium
Interview Round: Onsite
## ML / Growth Scenario
You own a system that sends **promotion offers** (e.g., "$10 off", "free delivery") to consumers to increase growth.
### Prompt
Design an approach to decide:
- **Who** should receive a promo
- **What** promo to send (offer type/amount)
- **When** to send it
Constraints and concerns:
- Limited promo budget
- Risk of giving discounts to users who would have ordered anyway
- Need to measure **incremental lift** (not just conversion)
- Avoid harming long-term margin or creating promo addiction
Explain your modeling/experimentation strategy, data needs, evaluation metrics, and how you would deploy and monitor it.
Overview: This question evaluates the ability to design and operationalize ML-driven promotion targeting and measurement systems, assessing competencies in causal inference and uplift estimation, experimentation design, metric selection, budget-aware optimization, and monitoring for long-term impact.