Scale Engineer

Software Engineer

Software EngineerE3Medium to Hard

The DoorDash Software Engineer E3 interview process is designed to assess a candidate's technical skills, problem-solving abilities, and cultural fit for the company. It typically involves multiple rounds, including HR screening, technical interviews focusing on data structures and algorithms, system design, and behavioral questions. The goal is to identify candidates who can contribute effectively to DoorDash's engineering teams and uphold its values.

Rounds·4

Timeline·~7d

Experience·2 - 5 yrs

Comp band·US$110000 - US$150000

Interview time·180 min

Evaluation

What they measure.

  • Problem-solving skills
  • Algorithmic thinking
  • Data structure knowledge
  • Coding proficiency
  • System design capabilities
  • Communication skills
  • Teamwork and collaboration
  • Cultural alignment with DoorDash values

Preparation

How to prepare.

Tips

  1. Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, graph traversal).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium and hard difficulty.
  3. Study system design concepts, including scalability, availability, reliability, and common design patterns (e.g., load balancing, caching, message queues).
  4. Prepare for behavioral questions by reflecting on your past experiences using the STAR method (Situation, Task, Action, Result).
  5. Research DoorDash's mission, values, and recent news to understand the company's business and culture.
  6. Prepare thoughtful questions to ask the interviewers about the role, team, and company.

Study plan

Fig · Study plan — 04 phases

01 / 04
01

Phase 01 of 04

Data Structures and Algorithms

Weeks 1-2: Data Structures & Algorithms Fundamentals. Practice 2-3 problems daily.

Weeks 1-2: Focus on core data structures and algorithms. Cover arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), graphs, and hash tables. Practice common algorithms like sorting (quicksort, mergesort), searching (binary search), recursion, and dynamic programming. Aim to solve 2-3 problems per day.

Questions

Commonly asked.

  • Given an array of integers, find the contiguous subarray with the largest sum.
  • Design a system to shorten URLs.
  • Explain the difference between a process and a thread.
  • Describe a time you disagreed with a teammate and how you resolved it.
  • How would you optimize a slow-loading web page?
  • Implement a function to reverse a linked list.
  • What are the trade-offs between using a relational database and a NoSQL database?
  • Tell me about a project you are particularly proud of.
  • How do you handle ambiguity in requirements?
  • Design a notification system for a large-scale application.

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

San Francisco, CA

Interview focus

System design for distributed systemsScalability and performance optimizationExperience with cloud platforms (AWS, GCP)

Common questions

  • How would you design a system to handle real-time order updates for Dashers?
  • Discuss a challenging technical problem you faced and how you solved it.
  • Explain the trade-offs between different database solutions for a high-throughput system.

Tips

  • Be prepared to discuss your experience with microservices architecture.
  • Familiarize yourself with common distributed system patterns.
  • Highlight any experience with large-scale data processing.

Rounds

Round-by-round.

Expand a step for evaluation criteria, sample questions, and prep notes.

DSA

Coding questions at DoorDash.

Frequently reported on DoorDash loops

View all at DoorDash

Other guides

More at DoorDash.