Instacart Software Engineer Interview Guide

tl;dr

Instacart serves millions of shoppers with over 85,000 stores, and has created over 185,000 jobs in its mission to redefine how people shop for groceries. Software engineers at Instacart aren’t just part of a famously great company culture, they’re also supporting local businesses in communities all over the U.S. and Canada with over 1,500 retail banners.

The interview loops at Instacart are fairly standardized, so whether you’re interviewing for infrastructure or product, you’ll likely face the same interview process across teams. For all of its teams, Instacart tends to prefer software engineers with experience in at least some of the following:

• High-level system design
• Machine learning
• Scalable data pipelines
• Mentorship and collaboration
• Proficiency in Python, Ruby on Rails, or Go

What does an Instacart Software Engineer do?

Instacart engineers help shape the future of how people get and prepare food, so Instacart Software Engineers are at the cutting edge of bringing blue-sky projects into reality. Among several new tech initiatives they’re pursuing, Instacart recently acquired Caper AI to help build smarter shopping carts, so many roles now prioritize LLM and machine learning experience.

Instacart’s engineering teams are always looking to iterate on the process of buying groceries, so a user-centered approach to products and features is extra valuable. An advantage of being an Instacart Software Engineer is the focus on cross-team collaboration. Because Instacart is such a large distributed company, collaborative engineers are seen as good candidates.

The average total compensation across software engineering levels at Instacart are:

• (Entry-level) Software Engineer: $222K
• Software Engineer: $279K
• Senior Software Engineer: $342K
• Senior Staff Software Engineer: $728K

Before you apply

• Brush up on data structures; this process is heavier on coding rounds than most software engineering loops
• Research recent interview questions asked at Instacart.
• Try out the Instacart platform so you can speak to features (and grab a snack!)

Interview process

Instacart was recently rated by BuiltIn as one of the best workplaces of 2024, and is known in the industry for its award-winning workplace culture, which makes theirs a highly competitive interview process.

Unlike other large tech companies, Instacart doesn’t have a dedicated “culture” or “values” interview—their recruiters assess candidates for culture-fit qualities like collaboration, communication, and agility throughout the interview process. Instacart likes to say that “no matter what you bring to the potluck, there's a seat at the table for you.”

For more junior roles, candidates apply to an open-ended job description, and are placed on a team by the hiring manager after passing their interviews. Applications are generally more role-specific for more senior engineering roles. The questions in this guide are based on the experiences of developers interviewing for senior-level roles.

Instacart hiring loops tend to be fairly standardized. Typically, the interview process at Instacart can take 4–6 weeks.

Applicants generally describe three stages for the interview loop at Instacart:

1. A recruiter phone screen to ensure you meet the minimum requirements for the role
2. Technical screens, which are generally split into two separate interviews
3. Onsite interviews, which are multi-hour and cover both behavioral and technical topics

1. Recruiter phone screen

There may be some light technical questions during the recruiter screen, but usually the focus of this 45-minute call is on behavioral questions and typical recruiter logistics questions.

Be ready to talk about your previous work history and skills as they relate to the job description and why you’re passionate about innovating in the field of grocery shopping, scalable data pipelines, mentorship, and machine learning (aka “why Instacart”).

Sample questions include:

• Walk me through your resume.
• Why Instacart?
• What are you looking for in your next role?
• Please share an instance when you and your manager disagreed.
• Tell me about a time you assisted one of your colleagues outside of your responsibilities. What happened and how did it go?
• Tell me about a process or tool that you learned or developed at your previous job that you feel will be valuable in your future position at Instacart.

2. Technical interviews

You’ll have at least one (usually two) hour-long online skills assessments on CodeSignal during the next phase of interviewing at Instacart. The questions in these assessments tend towards the more abstract or theoretical, rather than a more case-study-focused assessment you’d find at a company like Roblox.

Comparing the philosophy of technical rounds, companies like Spotify and Google primarily care about your thought process (the “how”), whereas Meta, Amazon, and Instacart care mainly about your results (the “what.”) Make sure you’re focusing on passing your tests as efficiently as possible; these interviewers may not be as generous with their hints as those at more “how”-focused companies.

The first technical assessment will be unsupervised, and the second will be overseen by a member of the engineering team:

Unsupervised tech screen

During this round, you’ll take a 1-hour timed online skills assessment on CodeSignal. Questions asked during this round and the following supervised round are often on similar abstract, technical topics.

Supervised tech screen

After the preliminary assessment is another 1-hour CodeSignal task, supervised by a member of Instacart’s engineering team. If there are few applicants for a role, this screen may be optional.

Tech screen topics:

• Coding
• Data Structures like hash maps, trees, arrays, and linked lists
• String manipulation

Sample questions for both tech screens include:

• Find two integers in a list that sum to a third integer.
• Given a list of tuples featuring names and grades on a test, write a function normalize_grades to normalize the values of the grades to a linear scale between 0 and 1.
• Given an N-dimensional array (a nested list), convert it into a 1D array. The N-dimensional array can have any number of nested lists and each nested list can contain any number of elements. The elements in the nested lists are integers. Write a function that takes an N-dimensional array as input and returns a 1D array.
• Implement a Fibonacci sequence-based algorithm in three different methods: 1. Recursively 2. Iteratively 3. Using Memoization

3. Onsites

These four onsite interviews are typically scheduled back-to-back on the same day, and are designed to test your ability to collaborate, communicate, and solve ambiguous problems.

These are scheduled for four hours in total, but some candidates have mentioned interviewers really wanting to dig down and take longer, so be prepared to stay about an hour more. Despite the name, some applicants were able to complete these over Zoom. If you live near an Instacart office, though, you should expect to come in.

a. System design

This interview, typically an hour long, is looking for how you plan out a project from beginning to end.

At Instacart, you may still be asked behavioral-adjacent follow-up questions at this stage, like “have you tried this in personal projects?” or “how would you delegate work on this project with another developer?” So be prepared to communicate clearly and tangibly throughout. Typically, questions asked during these interviews come from a standardized list, but follow-up questions will be specific to what you answer.

Unlike at other tech companies like Google, which ask broader system design questions (i.e. “how would you build Netflix end-to-end?”), system design at Instacart tends to dig down into the nitty-gritty of one specific product or feature.

Questions in Instacart system design interviews tend to be clear, with smaller scope, to see how you handle details, and the questions always center on a hypothetical feature for Instacart. Generally, these interviews are conducted by a product manager, who will also be assessing how you interact with product and product statements just as much as how well you can design end-to-end systems.

Questions to prepare for:

• Design a product catalog.
• How would you communicate with a payment processor?
• Design a system for tracking shipments.

b. Two separate coding rounds

These two coding rounds, typically an hour long each, may be more difficult than your earlier rounds. You’ll be asked 2–3 questions in each round, and candidates are expected to correctly solve as many as possible. Questions asked in these rounds may build on each other, and will be more practical and focused on end-to-end problem-solving, but will still assess your theoretical knowledge as well.

These supervised whiteboard tasks assess your productivity more than your thought process, and are more like Meta’s interview process than Google’s. Because of this, questions are structured to give you as much information as possible upfront, so the engineers supervising you won’t expect you to ask many follow-up questions. In fact, many interviewers see candidates asking for hints or advice at this phase to be a disqualifying factor, so practice your independence here. Unlike in earlier coding rounds, these tasks already have built-in tests, so all you need to do is make sure they pass as efficiently as possible.

Topics include:

• String matching, tree traversal, file traversal
• Key-value storage and retrieval
• Coordinate matching
• Expression evaluation

Questions to prepare for:

• Implement a function that calculates the factorial of a given positive integer.
• Implement a simple key-value storage system that allows you to set, get, and delete key-value pairs. The system should be able to handle a large number of key-value pairs efficiently.
• Create a Python script for converting USD to euros. Additionally, discuss strategies for optimising API usage within this context.
• Develop a key-value datastore capable of historical value retrieval. It should handle multiple values for a single key at various timestamps. This datastore should support queries based on the key alone or the key along with a timestamp.
• Write an SQL query using a subquery that retrieves three columns: customerID, productID, and rating. Your task is to identify the top 10 products based on their ratings.

c. Bar-raiser interview

This hour-long conversation is a recent addition to the Instacart hiring loop. Bar-raiser interviews at Instacart focus on assessing your leadership and project execution skills. You’ll be asked about a past project to see where and how you go above and beyond, both technically and in terms of business impact, so be ready with numerical points of impact in both areas. You can think of this interview as being comparable to a final interview anywhere else.

Your hiring manager will want to hear about a recent project, with a particular highlight on the complex issues of your project and how you resolved those complexities. Make sure you’re not too general in your answers and that you’re able to slow down and speak about your project at various phases, including post-launch, during the project, managing collaboration, and facing technical challenges.

Unlike at companies like Dropbox, where infrastructure engineers’ bar-raiser questions go into great depth, and product prioritizes collaboration, hiring managers at Instacart will look for both core competencies at once and assess you for both areas of growth and potential teams where you might be the best fit.

Hiring managers at Instacart assess your collaboration skills in three areas:

• How you’ve collaborated through past areas of conflict
• How you’ve led projects to meaningful business impacts
• How you mentor other developers to measurable success

Candidates who get offers from Instacart can speak clearly on all three during their bar-raiser interview.

“What could have been better” and “what did you learn” are commonly asked follow-up questions in Instacart bar-raiser interviews, so great candidates know that projects where everything went perfectly aren’t necessarily the best for bar-raiser answers, since you want to display room to reflect and grow.

Great bar-raising candidates are able to think of the future of the project, not just current wins, and demonstrate long-term thinking.

Sample questions include:

• Tell us about a recent project from your resume. Can you take us through the process of how you delivered it from start to finish?
• What's your approach to cross-functional collaboration?
• Name a time when you had to make a product decision, but stakeholders wanted different things. What did you do?
• Tell me about a difficult problem you solved with a simple solution.
• Can you talk about a product launch you worked on? What was your involvement and what was the end result?

Additional resources

• Take our course to level up your software engineering skills.
• Get coaching and actionable feedback from software engineers at the level you aspire to land an offer for.
• Practice with mock interviews on the most common types of problems.

FAQs about the Instacart Software Engineer interview

What can I expect from my SWE interview at Instacart?

When interviewing at Instacart, you can expect three main phases (recruiter, technical screens, and onsite) that assess your ability to solve coding problems efficiently and correctly, answer behavioral questions, and reflect on past projects with an eye for future iteration and business improvements.

On average, how much do Instacart Software Engineers typically make?

The average total compensation across software engineering levels at Instacart are:

• (Entry-level) Software Engineer: $222K
• Software Engineer: $279K
• Senior Software Engineer: $342K
• Senior Staff Software Engineer: $728K

How long is the typical Instacart interview process?

Typically, interview loops at Instacart take 4–6 weeks, but popular or senior-level roles may see delays.

How should I prepare for a software engineering interview at Instacart?

• Be ready to talk through a recent project stressing measurable business impact
• Check out the Instacart tech blog to make sure you know about the latest projects
• Brush up on data structures; this process is heavier on coding rounds than most software engineering loops
• Research recent interview questions asked at Instacart.
• Try out the Instacart platform so you can speak to features (and grab a snack!)

Will I have in-person interviews at Instacart?

Instacart is a flex-first workplace, so if you live near one of the three main office locations in San Francisco, New York, or Toronto, you can expect to interview in person, but will probably have flexibility about where you work if you get the job.