Problem database last updated: June 20, 2025
15 problems · 4 Easy, 8 Medium, 3 Hard · Ranked #108 of 458
4 Easy
27% · avg 23%
8 Medium
53% · avg 59%
3 Hard
20% · avg 18%
Based on 15 reported problems, Instacart interviews are in line with industry averages - 20% Hard vs 18% overall. The majority (53%) of questions are Medium difficulty, which is typical for companies that want to see solid fundamentals without excessive trick questions.
Compared to the industry average, Instacart puts unusual emphasis on greedy (26.7% of problems, 3.2x the industry average), sorting (33.3% of problems, 2.3x the industry average), binary-search (20% of problems, 2.3x the industry average). If you're short on time, these are the categories to double down on.
The most common topics are array (80%), sorting (33.3%), string (26.7%), greedy (26.7%). Problems below are sorted by frequency, the ones at the top are asked most often.
| Problem | Difficulty | Frequency | Topics | |
|---|---|---|---|---|
Time Based Key-Value Store Design a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key's value at a certain... | Medium | Very Likely | hash-tablestringbinary-search | Solve |
Check if Every Row and Column Contains All Numbers An n x n matrix is valid if every row and every column contains all the integers from 1 to n (inclusive). | Easy | Very Likely | arrayhash-tablematrix | Solve |
Find First and Last Position of Element in Sorted Array Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. | Medium | Very Likely | arraybinary-search | Solve |
Squares of a Sorted Array Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order. | Easy | Likely | arraytwo-pointerssorting | Solve |
Wildcard Matching Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '' where: | Hard | Likely | stringdynamic-programminggreedy | Solve |
Valid Number Given a string s, return whether s is a valid number. | Hard | Likely | string | Solve |
Non-overlapping Intervals Given an array of intervals intervals where intervals[i] = [starti, endi], return the minimum number of intervals you need to remove to make the rest of the int... | Medium | Likely | arraydynamic-programminggreedy | Solve |
Average Waiting Time There is a restaurant with a single chef. You are given an array customers, where customers[i] = [arrivali, timei]: | Medium | Likely | arraysimulation | Solve |
Minimum Number of Arrows to Burst Balloons There are some spherical balloons taped onto a flat wall that represents the XY-plane. The balloons are represented as a 2D integer array points where points[i]... | Medium | Likely | arraygreedysorting | Solve |
Merge Intervals Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cove... | Medium | Likely | arraysorting | Solve |
Maximum Number of Events That Can Be Attended You are given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi. | Medium | Likely | arraygreedysorting | Solve |
Best Time to Buy and Sell Stock You are given an array prices where prices[i] is the price of a given stock on the ith day. | Easy | Likely | arraydynamic-programming | Solve |
Search Insert Position Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were ins... | Easy | Likely | arraybinary-search | Solve |
Valid Sudoku Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules: | Medium | Likely | arrayhash-tablematrix | Solve |
Word Search II Given an m x n board of characters and a list of strings words, return all words on the board. | Hard | Likely | arraystringbacktracking | Solve |
Time Based Key-Value Store
SolveDesign a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key's value at a certain...
Check if Every Row and Column Contains All Numbers
SolveAn n x n matrix is valid if every row and every column contains all the integers from 1 to n (inclusive).
Find First and Last Position of Element in Sorted Array
SolveGiven an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value.
Squares of a Sorted Array
SolveGiven an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.
Wildcard Matching
SolveGiven an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '' where:
Non-overlapping Intervals
SolveGiven an array of intervals intervals where intervals[i] = [starti, endi], return the minimum number of intervals you need to remove to make the rest of the int...
Average Waiting Time
SolveThere is a restaurant with a single chef. You are given an array customers, where customers[i] = [arrivali, timei]:
Minimum Number of Arrows to Burst Balloons
SolveThere are some spherical balloons taped onto a flat wall that represents the XY-plane. The balloons are represented as a 2D integer array points where points[i]...
Merge Intervals
SolveGiven an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cove...
Maximum Number of Events That Can Be Attended
SolveYou are given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi.
Best Time to Buy and Sell Stock
SolveYou are given an array prices where prices[i] is the price of a given stock on the ith day.
Search Insert Position
SolveGiven a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were ins...
Valid Sudoku
SolveDetermine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:
Word Search II
SolveGiven an m x n board of characters and a list of strings words, return all words on the board.
Frequency scores are based on crowdsourced interview reports. A higher score means the problem has been reported more often in recent Instacart interviews.
Very Likely
75-100%
Likely
50-74%
Sometimes
25-49%
Rare
0-24%
Instacart interviews focus heavily on array, sorting, string problems. If you're short on time, these are the categories to prioritize. The problems on this page are sorted by frequency, so start from the top and work your way down.
Beyond solving problems, practice explaining your approach. Instacart interviewers care about your thought process - how you break down a problem, consider edge cases, and evaluate tradeoffs between solutions. A clean O(n) solution you can explain clearly beats an O(log n) solution you can't articulate.
Looking for more companies? Browse all 458 companies in our directory, or sharpen your fundamentals with our free data structure visualizers and AI-powered DSA tutor.
Instacart has been reported to ask 15 distinct coding problems. The most common topics are array, sorting, string. 4 are Easy difficulty, 8 are Medium, and 3 are Hard. Problems are sorted by frequency - the ones at the top are asked most often.
Based on 15 reported problems, Instacart interviews are in line with industry averages - 20% Hard vs 18% overall. 53% of questions are Medium difficulty. Focus on the high-frequency Medium problems first, then work through the Hard ones.
Start with the highest-frequency problems listed on this page. Focus on the core topics: array, sorting, string. Practice solving them under time pressure and explaining your approach out loud. Mock interviews with AI can simulate the real experience.
Simulate a real Instacart coding interview with an AI interviewer. Get a scorecard with specific feedback on your problem-solving, code quality, and communication.
Simulate a Instacart interview with AIarrow_forward
