Handle merchant complaint about excessive demand
Company: DoorDash
Role: Data Scientist
Category: Behavioral & Leadership
Difficulty: medium
Interview Round: Onsite
# Handle a Merchant Complaint About Excessive Demand
A merchant complains that DoorDash is sending more demand than their store can handle. They say the extra order volume is hurting operations, increasing wait times, and creating a poor experience for customers and couriers.
You are the Data Scientist asked to help product and operations respond.
### Constraints & Assumptions
- Treat the complaint as a signal to investigate, not as proof of the full root cause.
- Consider the interests of merchants, customers, dashers, and DoorDash.
- Propose both short-term mitigations and longer-term product or model improvements.
- Include metrics that show whether the response helped without simply suppressing growth.
### Clarifying Questions to Ask
- Is this one merchant, a chain, a cuisine segment, or a broader market pattern?
- Which experience is failing: prep time, order accuracy, cancellations, wait time, ratings, or support contacts?
- Did recent promotions, ranking changes, dispatch changes, or menu changes increase demand?
- Does the merchant have tooling to pause, throttle, adjust prep time, or limit menu items?
### What a Strong Answer Covers
- Validate the complaint with data: order volume, prep time, dasher wait, cancellation rate, late deliveries, refunds, ratings, and support tickets before and after the demand spike.
- Segment by merchant, time of day, menu item, order size, promotion, and channel.
- Diagnose whether the root cause is demand surge, inaccurate prep-time prediction, merchant staffing, menu complexity, batching, or dispatch timing.
- Propose interventions such as throttling, dynamic prep times, capacity controls, temporary promotion changes, merchant alerts, menu simplification, and operational playbooks.
- Evaluate impact using merchant health, customer experience, dasher wait, fulfilled orders, revenue, and long-term retention.
- Communicate trade-offs transparently to cross-functional stakeholders.
### Follow-up Questions
- How would you decide whether to reduce the merchant's exposure in ranking?
- What metric would detect whether throttling went too far?
- How would you handle this differently for a strategic enterprise merchant?
- What product feature would prevent similar complaints in the future?
Quick Answer: DoorDash data scientist case prompt on investigating a merchant complaint about excessive demand, diagnosing operational bottlenecks, balancing marketplace stakeholders, and measuring product or operations interventions.
Solution
# Solution Alignment Notes
Treat the merchant complaint as a data signal to investigate. Balance merchant capacity, customer reliability, dasher wait time, and marketplace growth when recommending mitigations.
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### 1) Triage: verify the issue and quantify impact
Start by aligning on what “too much traffic” means operationally:
- Max orders/hour the kitchen can handle
- Staffing level by daypart
- Whether the pain is from *order volume*, *order timing* (spikes), or *order complexity*
Pull a before/after view (e.g., last 2 weeks vs prior 4 weeks) for that merchant (and comparable merchants):
- Orders/hour by daypart; peakiness (P95 orders/hour)
- Prep time (P50/P90) and variance
- Merchant cancellation rate and reason codes
- Late orders, refunds, missing items
- Dasher wait time at store
If merchant KPIs degraded at the same time volume spiked, the complaint is likely valid.
### 2) Diagnose root causes (common patterns)
**A. Demand spike drivers**
- Promotions, pricing changes, featured placement, search ranking changes
- Local events or competitor outage
**B. Capacity mismatch**
- Merchant hours/availability inaccurate (store marked open while understaffed)
- Menu item availability not updated (out-of-stock leading to substitutions/delays)
**C. Incorrect operational parameters**
- Prep-time settings too low → dashers arrive early and congestion builds
- No effective throttling / order caps during peak
**D. Marketplace spillovers**
- Delivery radius too large bringing in extra demand
- Reassignment/batching causing bursty arrivals at the merchant
### 3) Interventions (balance all sides)
Pick the least invasive intervention that restores service quality.
**Merchant-protecting controls**
- **Order throttling / caps**: max orders per 15 minutes during peak.
- **Busy mode** / dynamic prep times based on real-time backlog.
- **Temporary pause** or reduced delivery radius during staffing shortages.
- Improve menu management (auto-86 items when out-of-stock signals appear).
**Consumer experience safeguards**
- Update quoted ETAs and availability transparently instead of accepting orders that will fail.
- If throttling reduces supply, ensure ranking/search reflects availability to reduce frustration.
**Dasher experience safeguards**
- If the merchant is congested, reduce early arrivals by delaying dispatch or improving ready-time prediction.
**Operational partnership**
- For top merchants, offer ops playbooks: staffing guidance for expected demand, peak-hour scheduling.
### 4) Measurement and monitoring
**Primary success outcomes (merchant health):**
- Merchant cancellation rate ↓
- Prep time P90 ↓ (or stabilizes)
- Dasher wait time ↓
- Merchant satisfaction / complaint volume ↓
**Guardrails:**
- Consumer conversion and completion rate (don’t over-throttle)
- On-time delivery and refund rate
- Merchant revenue (avoid unnecessary demand suppression)
**Evaluation design:**
- If rolling out throttling logic, do merchant-level A/B (or stepped-wedge rollout) because interference is localized.
- Monitor for demand shifting to nearby merchants (good) vs overall demand loss (bad).
### 5) Recommendation
Treat this as a service-quality risk: accept fewer orders but deliver them reliably.
Implement short-term throttles and correct prep-time/availability settings immediately, while building a longer-term dynamic capacity model (predict max sustainable order rate by daypart) to prevent recurrence.