DoorDash Software Engineer Interview Questions

Behavioral Questions (15)

1. 1.Describe a situation where you had to ship code under tight time pressure. What corners did you cut, and how did you ensure the system stayed reliable?

   easy~3 min

   What interviewers look for

   • Made conscious decisions about what to cut vs. what was non-negotiable for reliability or user experience
   • Put monitoring, alerting, or rollback plans in place to catch issues quickly in production
   • Communicated timeline constraints and technical risks clearly to stakeholders
   • Followed up after launch to address technical debt or improve the solution

   Likely follow-ups

   • How did you decide which parts of your usual development process to skip or streamline?
   • What would you have done differently if you had twice as much time for that project?

   Company context

   DoorDash's logistics business operates in real-time with millions of daily orders, where speed of delivery and feature iteration directly impacts consumer experience and Dasher earnings. The 'Operate at Speed' principle means engineers must regularly ship under pressure while maintaining the reliability that the three-sided marketplace depends on. This question tests a candidate's ability to make smart tradeoffs when time is constrained.

2. 2.You're implementing a feature flag for rolling out batched order assignments to Dashers. The feature affects both order assignment latency and Dasher earnings. How would you design the flag system to safely test this across different markets?

   easy~4 min

   What interviewers look for

   • Discusses gradual rollout strategy with market-based segmentation to isolate impact
   • Identifies key metrics to monitor for both consumer wait times and Dasher earnings
   • Considers rollback mechanisms and circuit breakers for real-time dispatch systems
   • Mentions A/B testing framework or statistical significance for marketplace changes

   Likely follow-ups

   • What specific metrics would you track to ensure this doesn't hurt Dasher retention?
   • How would you handle the case where batching improves efficiency but increases consumer wait times?

   Company context

   DoorDash operates a three-sided marketplace where feature changes must balance consumer, Dasher, and merchant needs. The company's 'Three-Sided Marketplace Thinking' principle requires engineers to reason about second-order effects across all stakeholders. Feature flags are critical for safely deploying changes to real-time dispatch systems that affect millions of daily deliveries.

3. 3.Design the restaurant onboarding system for DoorDash Marketplace. We need to handle 5,000 new merchant signups per day and ensure they can start receiving orders within 2 hours of completing their application.

   easy~3 min

   What interviewers look for

   • Designs for three-sided marketplace thinking by considering how merchant onboarding affects consumer selection and Dasher order availability
   • Proposes async processing workflow to handle verification steps without blocking the merchant experience
   • Considers geographic distribution and local compliance requirements for different markets
   • Includes monitoring and alerting for SLA violations on the 2-hour promise

   Likely follow-ups

   • What happens if the menu parsing service is down but a merchant needs to go live immediately?
   • How would you handle onboarding a large chain restaurant with 500 locations at once?

   Company context

   DoorDash's 'Make Room at the Table' value emphasizes supporting diverse merchants, especially smaller local businesses who may need simplified onboarding flows. The company's marketplace growth depends on efficient merchant acquisition while maintaining quality standards for consumers and ensuring Dashers have profitable orders to deliver.

4. 4.Tell me about a time you had to convince someone from a non-engineering function to change their approach to support a technical solution. What was your strategy?

   easy~3 min

5. 5.DoorDash's consumer app shows 'Delivered' when a Dasher marks an order complete, but we're getting complaints that 15% of orders marked delivered haven't actually reached customers. Estimate the annual revenue impact of this problem and walk me through how you'd prioritize fixing it.

   easy~4 min

6. 6.Tell me about a time you had to make a technical decision that would affect multiple user groups differently. Walk me through your thought process and how you weighed the tradeoffs.

   medium~4 min

7. 7.Our dispatch service is experiencing timeout issues when Kafka is under heavy load during peak dinner hours. The service needs to assign orders to Dashers within 10 seconds or the delivery promise fails. Walk me through how you'd debug and fix this.

   medium~5 min

8. 8.Design a system to handle DashPass subscription billing across 4,000+ cities globally. The system needs to process 50 million monthly charges while handling different payment methods, currencies, and local tax requirements.

   medium~4 min

9. 9.Describe a time when you took ownership of a problem that wasn't clearly in your scope. What made you step up, and how did you drive it to resolution?

   medium~4 min

10. 10.We're seeing 20% week-over-week growth in grocery orders, but Dasher earnings per delivery are dropping because grocery trips take longer than restaurant deliveries. Estimate how much we'd need to increase grocery delivery fees to maintain Dasher earnings parity, and what impact that might have on consumer demand.

    medium~5 min

11. 11.Tell me about the most challenging situation you've faced with a teammate in the last two years. What made it difficult, and how did you work through it?

    hard~5 min

12. 12.Design a real-time pricing system that adjusts delivery fees based on Dasher supply and consumer demand. The system needs to handle 100,000 pricing decisions per minute while ensuring Dashers see consistent pricing for at least 5 minutes.

    hard~5 min

13. 13.Design the order batching system for the Dasher Platform. The system assigns multiple orders to a single Dasher to improve efficiency, but needs to balance delivery time promises to consumers with Dasher earnings optimization across 25 million monthly active Dashers.

    hard~5 min

14. 14.Tell me about a time you had to lead a technical decision that required buy-in from engineers more senior than you. How did you build consensus?

    hard~5 min

15. 15.DoorDash is considering expanding DashPass to include exclusive access to high-demand restaurants during peak hours. Estimate the potential revenue impact of this feature and analyze whether it aligns with our marketplace strategy.

    hard~5 min