Instacart interview notes, page 3 of 13

Large Enterprises

Most of these Instacart write-ups come from Software Engineers (88), then Data Scientists (28) and Machine Learning Engineers (5). The most reported rounds are the technical phone screen (93), the system design round (13), the behavioral / leadership round (6) and the product sense round (6).

128 interview notes · updated Jul 2026

Instacart·Software Engineer·Technical Phone Screen

Apr 2026

Interviewed at Instacart for a software engineering role. One coding problem, pretty focused on state management logic. Felt straightforward on the surface but the edge cases tripped me up a bit.

Design a method that registers a timestamp for a worker, where the timestamp means 'clocking in' if the worker is currently out of the office, and 'clocking out' if they're already in. The system should infer which one based on current state.

“My first instinct was to reach for a hashmap tracking each worker's status, toggle on each call.”

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Instacart·Software Engineer·Onsite - Behavioral / Leadership

Apr 2026

Behavioral round at Instacart for a software engineering role. Just one question but they really sat in it with me, lots of follow-ups about the relationship side of things not just what decision got made.

Tell me about a time you had a conflict with a coworker, manager, or cross-functional partner. What was the disagreement, how did you handle the conversation, and what came out of it? How did you keep the relationship intact while still pushing toward the right call?

“The relationship piece is what tripped me up.”

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Instacart·Software Engineer·Technical Phone Screen

Apr 2026

Instacart software engineer interview with a grid traversal problem that sounds straightforward until you actually sit down with it. The edge cases pile up fast and I spent way too long second-guessing the error handling.

You're given a 2D character grid, a starting position, and a sequence of move directions (up, down, left, right). Traverse the grid following the moves and build a password string by appending each visited cell's character, but skip duplicates of the last appended character. Cells marked '#' are blocked. If any move goes out of bounds or into a blocked cell, return an error immediately. What's your approach and what are the time and space complexities?

“I started with the traversal logic and that part felt fine, just track position and simulate each move.”

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Instacart·Data Scientist·Onsite - Behavioral / Leadership

Apr 2026

Cross-functional collaboration question at Instacart for a data scientist role. Pretty standard behavioral territory but the scope negotiation piece had some teeth to it.

How do you collaborate with product, engineering, design, and sales teams? Walk us through the cadence, artifacts, and alignment rituals you rely on.
Tell me about a time you resolved a priority conflict or negotiated scope without having formal authority. What was your escalation path, what trade-offs did you make, and what was the measurable result?

“I rambled a bit here.”

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Instacart·Data Scientist·Recruiter / HR Screen

Apr 2026

Screened for a Data Scientist role at Instacart. Just one question but it packed a lot in, basically a compressed life story plus a pitch plus a gap confession all in 90 seconds.

In 60 to 90 seconds, walk me through your career so far as it relates to this role. Include two specific outcomes you drove with numbers attached, the most recent tech stack you picked up, and one skill gap you are currently working on. Then explain why you want this role, why now, and how it connects to where you want to be in two years.

“This is a lot to cram into 90 seconds and I did not pull it off cleanly.”

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Instacart·Software Engineer·Onsite - System Design / Architecture

Apr 2026

System design round at Instacart for a software engineer role. The question was a full inventory management system design, which sounds scoped until you realize they want you to cover basically everything: data model, APIs, scaling, consistency. A lot to get through in one session.

Design an inventory management system that handles stock tracking, order processing, and real-time updates. Walk through the key components, data model, API design, scalability approach, and how you'd handle consistency.

“This is a deceptively wide question.”

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Instacart·Software Engineer·Technical Phone Screen

May 2026

Technical phone screen for a software engineer role at Instacart. One meaty parsing question that took up most of the time, and the discussion around it went pretty deep into tokenization and complexity analysis.

Given a symbolic arithmetic expression as a string (with integer constants, up to two named variables, binary + and - operators, optional whitespace, and optional nested parentheses), evaluate it and return the result as a canonical reduced form like `a*x + b*y + c`. Walk through your tokenization approach, parsing strategy, and time complexity.

“This one took me a second to even understand what 'canonical form' meant in context.”

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Instacart·Software Engineer·Technical Phone Screen

May 2026

Instacart coding round focused on a multi-level database simulation with banking entities. The first three levels were pretty standard CRUD and aggregation stuff, but level 4 is where things got interesting and honestly a bit rough.

Design and implement a backup function that captures a full snapshot of the current database state, tagged with a given timestamp.
Implement a restore function that rolls the database back to a snapshot at a given timestamp, then re-applies any scheduled operations that fall between that timestamp and the current time.
How would you handle a restore call when no snapshot exists for the requested timestamp?
What should happen if a restore operation is triggered while another restore is already in progress?

“Seemed manageable at first.”

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Instacart·Software Engineer·Hiring Manager Screen

May 2026

Bizops interview at Instacart with one open-ended metrics question. Short but the kind of question that looks easy until you're actually in it.

What metric would you want to track for Instacart, and how would you go about getting the data to answer it?

“I picked something around order frequency per customer and talked through retention logic, but I fumbled the second half about where the data actually lives.”

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Instacart·Software Engineer·Technical Phone Screen

May 2026

Instacart software engineer round focused entirely on writing unit tests for a priority boarding simulation. Pretty thorough problem with a lot of edge cases to think through, and the discussion around property-based testing was where things got interesting.

Write a comprehensive set of unit tests for a priority-boarding bus simulation where priority passengers board first in arrival order, remaining capacity fills with non-priority passengers in arrival order, and the implementation returns both the boarded list and the left-behind list.

“The edge cases are where this gets meaty.”

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