Scale Engineer

Engineer

Software EngineerL3Medium

Instacart's Software Engineer L3 interview process is designed to assess a candidate's foundational technical skills, problem-solving abilities, and cultural fit within the company. The process typically involves multiple rounds, starting with an initial screening and progressing through technical interviews and a final hiring manager discussion.

Rounds·3

Timeline·~14d

Experience·1 - 3 yrs

Comp band·US$100000 - US$130000

Interview time·150 min

Evaluation

What they measure.

  • Problem-solving skills
  • Data structures and algorithms knowledge
  • Coding proficiency
  • System design fundamentals
  • Communication skills
  • Teamwork and collaboration
  • Cultural fit and alignment with Instacart's values

Preparation

How to prepare.

Tips

  1. Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, recursion).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium-difficulty problems.
  3. Understand basic system design concepts, such as scalability, availability, and trade-offs.
  4. Prepare to discuss your past projects in detail, focusing on your contributions and the challenges you faced.
  5. Research Instacart's products, mission, and values to tailor your answers.
  6. Practice behavioral questions using the STAR method (Situation, Task, Action, Result).
  7. Be ready to explain your thought process clearly and concisely during coding exercises.

Study plan

Fig · Study plan — 04 phases

01 / 04
01

Phase 01 of 04

Data Structures and Algorithms Fundamentals

Weeks 1-2: Data Structures (Arrays, Lists, Trees, HashMaps) & Basic Algorithms (Sorting, Searching, Recursion).

Weeks 1-2: Focus on core data structures like arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), and hash tables. Practice problems related to these structures, emphasizing time and space complexity analysis. Cover basic algorithms like sorting (quicksort, mergesort), searching (binary search), and recursion.

Questions

Commonly asked.

  • Write a function to reverse a linked list.
  • Given an array of integers, find the two numbers that add up to a specific target.
  • Explain the difference between a process and a thread.
  • How would you design a URL shortener?
  • Tell me about a time you disagreed with a teammate and how you resolved it.
  • What are your strengths and weaknesses?
  • Describe a situation where you had to deal with ambiguity.

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

Remote

Interview focus

Adaptability to different work environments.Communication skills in a diverse team.Understanding of local market trends (if applicable to the role).

Common questions

  • Tell me about a challenging project you worked on at your previous company.
  • How do you handle conflicting priorities?
  • Describe a time you had to learn a new technology quickly.

Tips

  • Research Instacart's presence and operations in this specific region.
  • Be prepared to discuss how your skills align with local team needs.
  • Highlight any experience working with diverse or international teams.

Rounds

Round-by-round.

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

Med

Technical Interview - Coding · 45 min · Software Engineer

This round typically involves a coding exercise, often conducted via a shared online editor. The interviewer will present a problem, and you'll be expected to write code to solve it. They will assess your ability to understand the problem, choose appropriate data structures and algorithms, write clean and efficient code, and test your solution thoroughly. Expect to explain your approach and justify your choices.

What they look for

A candidate who can translate a problem into working code.Someone who can think critically about their solution.A candidate who communicates their thought process effectively.

Evaluation

  • Correctness of the solution
  • Efficiency of the solution (time and space complexity)
  • Code clarity and readability
  • Ability to handle edge cases
  • Problem-solving approach

Sample questions

  • Given a binary tree, find its inorder traversal.

    Data StructuresTreesRecursion

  • Implement a function to find the kth smallest element in an unsorted array.

    AlgorithmsSortingQuickselect

Prep for this round

  1. 01Practice coding on platforms like LeetCode, HackerRank, or Coderbyte.
  2. 02Focus on understanding time and space complexity (Big O notation).
  3. 03Write clean, well-commented code.
  4. 04Think out loud and explain your thought process to the interviewer.
  5. 05Don't be afraid to ask clarifying questions.

Common rejection reasons

  • ×Inability to articulate thought process.
  • ×Poor coding practices (e.g., unreadable code, lack of comments).
  • ×Failure to consider edge cases.
  • ×Difficulty in debugging code.

DSA

Coding questions at Instacart.

Frequently reported on Instacart loops

View all at Instacart

Other guides

More at Instacart.