Offer

DoorDash Interview

New Grad Software Engineer

Applied through careers page, followed by a recruiter call, online assessment, technical phone screen, and a virtual onsite loop.

LogisticsBackground

The call focused on candidate background, motivation for joining DoorDash, and logistical preferences regarding location and team placement.

Why DoorDash?

Behavioral

Data StructuresAlgorithms

The assessment required clean, runnable code with consideration for edge cases.

The first problem involved a sliding window technique to find peak delivery volume.

The second problem required modeling a driver assignment system using a greedy approach with a min-heap.

Data StructuresSystem Design

The candidate implemented a merchant rating system using a hash map of deques to manage time-based expiration of reviews.

The interviewer probed for time complexity optimizations.

The discussion evolved into a bucketing approach by day to handle data more efficiently.

GraphsBitmasking

The problem required finding the shortest path for a driver to visit multiple locations and return to a depot.

The solution involved BFS combined with bitmasking to track the state of picked-up orders.

The candidate successfully implemented the logic but faced time constraints regarding full optimization.

System DesignScalability

The candidate proposed a architecture involving WebSockets for real-time updates and Kafka for location ingestion.

Geohashing was discussed as a strategy for managing driver locations at scale.

The discussion included trade-offs between consistency and latency, demonstrating an understanding of distributed systems.

Behavioral

The interview followed the STAR (Situation, Task, Action, Result) format.

The interviewer focused on conflict resolution and the ability to learn new technologies quickly.

Tell me about a time you disagreed with a teammate.

Behavioral

Do not overthink the interview process; interviewers are generally supportive and provide hints when candidates get stuck.
Prioritize preparation for behavioral rounds as they are a significant part of the evaluation.
Focus on demonstrating the ability to reason about scale and trade-offs during system design interviews.