SDE 1

Candidates describe two coding problems, usually LeetCode medium (sometimes harder), in about 70 minutes, followed by a work-style assessment of scenario questions and, in many accounts, a work simulation. Few candidates name the problems they got.

1. 1

   Given two arrays of passwords, determine whether each old password can be transformed into a subsequence of the corresponding new password by incrementing specific characters cyclically; return YES or NO for each pair

   DSA / Coding

2. 2

   Given an array of parcel weights, repeatedly select and remove either the first or the last parcel; the sum of the selected parcels is the efficiency. Return the maximum possible efficiency

   DSA / Coding

The first interview after the online assessment. Most accounts describe two DSA problems in about an hour, often written as word problems, with one or two Leadership Principles questions before or after the coding. Some candidates had it in person on a whiteboard.

1. 1

   House Robber: maximise the money robbed from a row of houses without robbing two adjacent houses

   DSA / CodingReported by 2 candidatesPractice on leetcode.com (opens in a new tab)

2. 2

   Count the inversions in an array

   DSA / Coding

3. 3

   Course Schedule II: find an order in which all courses can be taken, given their prerequisites

   DSA / CodingPractice on leetcode.com (opens in a new tab)

4. 4

   Tell me about a time when you had to implement something challenging.

   Behavioral

5. 5

   Insert Delete GetRandom O(1): design a set that supports insert, delete and getRandom in average O(1) time

   DSA / CodingMediumPractice on leetcode.com (opens in a new tab)

6. Show all 23 questions

   1. 6

      Top K Frequent Words: return the k most frequent words

      DSA / CodingMediumPractice on leetcode.com (opens in a new tab)

   2. 7

      Given a list of power sources, each with a certain amount of power, and n machines: each machine takes power from exactly one source, and a source can serve several machines as long as the total stays within its capacity. What is the maximum possible value of the minimum power assigned to any machine?

      DSA / Coding

   3. 8

      Top K Frequent Elements: return the k most frequent elements of an array

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   4. 9

      Generate all subsets of a set

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   5. 10

      Given a grid of integers, start at the top-left and reach the bottom-right without passing through negative values (they are roadblocks); return the maximum sum possible along the way

      DSA / Coding

   6. 11

      Keys and Rooms: can every room be visited, starting from room 0 and collecting keys?

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   7. 12

      Count the nodes of a complete binary tree efficiently

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   8. 13

      Sort the characters of a string in decreasing order of frequency

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   9. 14

      Aggressive Cows: place k cows in stalls to maximise the minimum distance between any two cows

      DSA / Coding

   10. 15

       Find the node with the highest edge score in a directed graph (ties go to the smallest index)

       DSA / CodingPractice on leetcode.com (opens in a new tab)

   11. 16

       House Robber II: the same problem with the houses arranged in a circle (asked as a follow-up)

       DSA / CodingPractice on leetcode.com (opens in a new tab)

   12. 17

       Given a binary tree (each node has at most two children), find the longest chain of even-valued nodes (example output: 3, along the path 2 -> 8 -> 10)

       DSA / Coding

   13. 18

       Given a sorted dictionary of an alien language, find the order of its characters

       DSA / CodingPractice on geeksforgeeks.org (opens in a new tab)

   14. 19

       Currency Converter: a graph problem where the candidate had to code everything from input handling to output printing, and the choice of data structure mattered

       DSA / Coding

   15. 20

       Given a list of words, find the next possible word based on what someone types (an autocomplete feature)

       DSA / Coding

   16. 21

       Path Sum II: find all root-to-leaf paths in a binary tree whose sum matches a given target

       DSA / Coding

   17. 22

       Given a 2D array of lecture timings [[start1, end1], [start2, end2], ...], return the minimum number of classrooms required to schedule all lectures without overlap in the same classroom. Follow-up: assign each lecture to a specific classroom

       DSA / Coding

   18. 23

       Design an automated system for a restaurant

       System Design

Three accounts had a low-level design round: model a system such as a task board or a board game with clean classes and modular code. One candidate's round ran over an hour and a half.

1. 1

   Low-level design: a manager can create a task and assign it to users; users can change a task's status (completed, not started, pending); the manager can view the tasks they assigned and each user can see who assigned a task. Follow-ups: thread safety, the entities and their relationships, database schema, API endpoints

   System Design

2. 2

   Design a billing service for a single AWS customer: given the customer's usage across AWS services and their rates, calculate the final bill. Requirements change during the round and the design has to adapt

   System Design

Usually a second DSA round: one or two problems plus Leadership Principles questions, sometimes with a project or resume discussion. One candidate was asked only for the approach on one of the problems.

1. 1

   Tell me about a time you did something outside your normal scope of work or responsibilities. What was the outcome?

   BehavioralReported by 3 candidates

2. 2

   Tell me about a time you missed a deadline. What could you have done better?

   BehavioralReported by 2 candidates

3. 3

   Longest Substring Without Repeating Characters

   DSA / CodingPractice on leetcode.com (opens in a new tab)

4. 4

   Longest Substring with At Most K Distinct Characters

   DSA / Coding

5. 5

   Tell me about a time you transferred your responsibilities.

   Behavioral

6. Show all 19 questions

   1. 6

      Given an array of stick lengths, you can connect any two sticks for a cost equal to the sum of their lengths. Find the minimum total cost to connect all the sticks into one

      DSA / Coding

   2. 7

      Given an array of positive and negative integers, find the length of the longest subarray with sum equal to 0

      DSA / Coding

   3. 8

      A variation of Rotting Oranges

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   4. 9

      All nodes at distance k in a binary tree (expected without storing parent pointers)

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   5. 10

      Create a playlist of a user's most frequently played songs, based on play count (asked to also give approaches using linear space)

      DSA / Coding

   6. 11

      Find the longest duplicated substring in a string; return an empty string if there is none

      DSA / Coding

   7. 12

      Find the maximum width of a binary tree

      DSA / CodingPractice on geeksforgeeks.org (opens in a new tab)

   8. 13

      Find the next greater element

      DSA / CodingPractice on geeksforgeeks.org (opens in a new tab)

   9. 14

      Is there a key event you want to mention as a career highlight? (follow-ups: what particular issue did you find and how did you solve it)

      Behavioral

   10. 15

       Clone a singly linked list using two pointers

       DSA / CodingPractice on geeksforgeeks.org (opens in a new tab)

   11. 16

       Design a 'find' command, like the one in a Unix system, to search for a file

       DSA / Coding

   12. 17

       Given a binary tree, print its inorder traversal, and explain every recursive call and its return value

       DSA / Coding

   13. 18

       Subtree of Another Tree: given two trees, check whether the second is a subtree of the first

       DSA / CodingPractice on leetcode.com (opens in a new tab)

   14. 19

       Given an n x n matrix where 1 is an empty cell, 2 a fresh vegetable and 3 a rotten vegetable: each day a fresh vegetable adjacent (up, down, left, right) to a rotten one becomes rotten. Return the number of days until the matrix stabilises

       DSA / Coding

Some candidates had a round that was entirely behavioural without calling it a bar raiser: from two to eight Leadership Principles questions, with cross-questioning on each answer.

1. 1

   Tell me about a time you received critical feedback. How did you deal with it?

   BehavioralReported by 2 candidates

2. 2

   Tell me about a time you didn't know how to proceed or how to solve a challenging problem. How did you work it out, and what options did you consider?

   BehavioralReported by 2 candidates

3. 3

   Tell me about a time when you had to implement something challenging.

   Behavioral

4. 4

   Tell me about a time you had to deep dive into subject matter.

   Behavioral

5. 5

   Tell me about a time you improved upon your shortcomings.

   Behavioral

6. 6

   Tell me about a time you missed a deadline. What could you have done better?

   Behavioral

7. 7

   Tell me about a time you needed to deep dive to find a problem or issue. How did you find it and what actions did you take?

   Behavioral

Mostly Leadership Principles: several behavioural questions with extensive follow-ups, and deep dives into past projects and decisions. Some candidates were also given a DSA problem in the last 15 to 20 minutes; others say there was no coding at all. The interviewer was sometimes a software development manager.

1. 1

   Koko Eating Bananas: find the minimum eating speed that finishes all the piles within the allowed hours

   DSA / CodingMediumPractice on leetcode.com (opens in a new tab)

2. 2

   Given the root of a tree, a source and a target, find the shortest path from the source to the target and print it as a string: 'A' for moving to the left child, 'B' for the right child, 'C' for moving to the parent (example: root 2 with children 1 and 4, source 1, target 4 gives "CB")

   DSA / Coding

3. 3

   Tell me about a time you did something outside your normal scope of work or responsibilities. What was the outcome?

   Behavioral

4. 4

   Tell me about a time you received critical feedback. How did you deal with it?

   Behavioral

5. 5

   Tell me about a time you started learning something that was new to you.

   Behavioral

6. Show all 15 questions

   1. 6

      Why did you choose this approach?

      Behavioral

   2. 7

      What alternatives did you consider?

      Behavioral

   3. 8

      What critical feedback did you receive, and exactly what changed after you received it?

      Behavioral

   4. 9

      Edit Distance: the minimum number of operations to convert one string into another

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   5. 10

      Word Break II: all the ways a string can be segmented into dictionary words

      DSA / CodingPractice on leetcode.com (opens in a new tab)

   6. 11

      Did you face any conflicting opinions in a team? How did you resolve it?

      Behavioral

   7. 12

      How did the idea for your major project come about?

      Behavioral

   8. 13

      What was the tech stack used for your major project, and why?

      Behavioral

   9. 14

      What were the technical and non-technical challenges, and how did you overcome them?

      Behavioral

   10. 15

       Reverse the alternate levels of a binary tree (the tree was not a perfect binary tree)

       DSA / Coding

Four accounts describe a hiring-manager round: a deep dive into projects and past decisions with behavioural questions, often with a hard DSA problem. Three of them include a discussion of how the candidate uses Gen AI.

1. 1

   A critical production issue at YouTube must be resolved within one hour, with the option to use AI tools. Discuss prioritisation and debugging strategy, use of monitoring and logs, how to use AI without over-relying on it, and decision-making under pressure

   Other

2. 2

   First Non-Repeating Character

   DSA / Coding

3. 3

   A variation of Maximum Product Subarray: also return the start and end indices of the subarray with the maximum product (follow-ups on zeros, multiple negatives and single-element arrays)

   DSA / Coding

A third coding interview in a few loops, combined with something else: a Gen AI discussion (two 2026 accounts) or a deep dive into the candidate's work.

1. 1

   How do you use Gen AI tools in your projects or personal work?

   Other

2. 2

   Have you used Gen AI tools for complex tasks?

   Other

3. 3

   Where do you think Gen AI tools should be used, and where not? Why?

   Other

4. 4

   Maintain a dynamic list of values with insertions, and answer queries for the current k-th largest value where k can change between queries (example: initial list [3, 7, 1], operations find k=3, insert 4, insert 9, find k=2, find k=4 gives 1, 7, 3)

   DSA / Coding

One account (2024) describes a system design round for SDE 1, followed by a discussion of the candidate's projects.

1. 1

   Design a bookstore system where multiple books exist, and return the count of a particular word (a fictional character) appearing in a specific book. Define the classes, objects and methods you would use

   System Design