Dropbox Software Engineer Phone Screen Questions
19+ questions from real Dropbox Software Engineer Phone Screen rounds, reported by candidates who interviewed there.
What does the Dropbox Phone Screen round test?
The Dropbox phone screen typically lasts 45-60 minutes and evaluates core Software Engineer fundamentals. Candidates should expect 1-2 algorithmic problems, basic system design discussion at senior levels, and questions about relevant experience. The goal is to confirm technical competence before bringing candidates onsite.
Top Topics in This Round
Dropbox Software Engineer Phone Screen Questions
PocketPills | SDE2 | GGN | Dec 24
Round 1: DS/PS Gas Station Singleton class and implementation. final, static, transient, synchronized and volatile keywords and their usage. Immutable class in Java and implementation. Round 2: System Design Design a...
Dropbox front end phone interview
A # | B # | | C <-- access # | | D # | E <-- access # |___ F ---- G # folders = [(\'A\', None), (\'B\', \'A\'), (\'C\', \'B\'), (\'D\',...
File access System I was asked the following question. If given the folder access tree and given query folder name, return TRUE|FALSE is user have access to it. for eg. below -...
Dropbox Interview | Phone Screen | Onsite | Questions | [Offer]
I had my onsite in January 2021. Phone: Game of Life (look it up) Onsite: 1. Reader-Writer Lock 2. All-Around Interview with a Hiring Manager 3. Id Allocator 4. Design a Logging Service The question packet and...
Dropbox phone interview
This was for sw2. I was supposed to search a dir to find files that have have the same content. Ex. hello.txt = "hello" and fjalfja.txt = "hello" and main.cpp,...
Dropbox Interview Telephonic + Onsite
YOE : 6+ Location : Bay area Telephonic: 1.) https://leetcode.com/discuss/interview-question/417262/dropbox-phone-screen-permissions-in-a-file-system They just expect you to save the data as dictionary with parent child relationship and just traverse it to find if the...
I got the file permission question similar to https://leetcode.com/discuss/interview-question/417262/dropbox-phone-screen-permissions-in-a-file-system and the follow-up was to modify implementation so that only the parent has access, for example: A -> B \t ----> C if we have...
Dropbox Phone Screen | Rejected
Had a phone screen with an arrogant L3 engineer and was rejected after coming up with working BFS solution. # # A # |___ B # | |___ C <-- access # | |___...
Dropbox | phone screen
I was asked the below question, during my phone screen today. Can anyone help me on this. Write a method for ColumnLayoutManager that takes input arguments: list of views with width and...
Dropbox @ Quality Engineer phone screen
Problem : A non-empty zero-indexed array A consisting of N integers is given. Array A represents a linked list. A list is constructed from this array as follows: \u2022 the first node (the...
Status: M.Tech new grad ( Computer Science and Engineering) Position: Software Engineer Location: Bangalore, India Date: 1 December 2019 There were four rounds, and it was an on-campus recruitment drive. Round 1: Online Assesment on...
Dropbox | Game of Life
Status: 6 Years of Experience Position: Senior SWE - Full Stack Location: HQ Phone Interview (1 hour): https://leetcode.com/problems/game-of-life/ Follow up: what if the board was very large, how would you deal with that? Interviewer said i...
Dropbox | Phone Screen | Find Duplicate File in System
Problem Statement: Given a file directory, return lists of files that are same in content. Example Input: /foo - /foo - /images - /foo.png <------. - /temp | same file contents -...
Dropbox | Phone Screen | Permissions in a File System
Hi, I got this question in dropbox in tech screening. And I am also posting my solution which I gave but I am very disappinted as I got reject. Please give...
Position: Front end Engineer Phone interview. 1. Implement getByClassName() javascript // element.children => HTMLCollection // element.className => string /** * @function getByClassName * @param {Element} root \u2013 The root of the DOM tree * @param {string} className * @return...
Dropbox | Phone Screen | Game of Life
Location: San Francisco Position: Senior SDE First round phone interview. https://leetcode.com/problems/game-of-life The interviewer made the question easier by returning the next state of board as opposed to modifying the original input. Input: [[0,1,0], [0,0,1], ...
Dropbox | Sr. Software Engineer | San Francisco [Reject]
Phone : https://leetcode.com/problems/find-duplicate-file-in-system/ Code was not supposed to run/compile but it was expected to write whole code and making sure that it would run. I had to ask...
## Problem Crawl a file system directory tree, collecting and processing files using BFS or DFS traversal. ## Likely LeetCode equivalent None identified with high confidence. ## Tags coding, graph, bfs, file_system, phone
## Problem You have a collection of letter tiles (possibly with duplicates) and a dictionary of valid words. Find all unique valid words that can be formed using any subset of the tiles (each tile used at most once). ```python def find_valid_words(tiles: list[str], dictionary: set[str]) -> list[str]: # tiles: list of single uppercase letters, e.g. ["A","A","B","T"] # Returns sorted list of unique valid words pass ``` **Example:** ``` tiles = ["A", "A", "B", "T"] dictionary = {"BAT", "TAB", "AAB", "AT", "BAA", "AABB"} -> ["AT", "BAT", "TAB"] # "AAB" not valid (only 1 B available but 2 A's -- wait: 2 A's ARE available, # so "AAB" is valid if in dictionary) ``` ## Round 1 - Coding Implement the search using backtracking with a frequency map of available tiles. ## Follow-ups 1. How do you use a trie (prefix tree) to prune the search space early when no word in the dictionary starts with the current prefix? 2. What is the worst-case time complexity with and without trie pruning? 3. How would you handle blank tiles (wildcards) that can represent any letter? 4. If the dictionary contains 500,000 words, what is a practical strategy to avoid memory issues with the trie?
What to Expect in the Dropbox Phone Screen Round
The Dropbox Software Engineer Phone Screen round has a specific calibration purpose distinct from other rounds in the loop. Across 19+ verified reports on LeakCode for this exact round type, the consistent expectations: clear scoping of the problem before diving into a solution, explicit reasoning about complexity, structured handling of edge cases, and the ability to discuss trade-offs between two reasonable approaches.
Reports tagged with the Phone Screen round at Dropbox show recurring patterns in difficulty and topic distribution. The Phone Screen round is typically 45-60 minutes; the interviewer is calibrated against a specific rubric. The discriminator between candidates who advance and candidates who do not is rarely the final correctness of the answer. It is the path: did you clarify, did you verbalize your approach, did you handle edge cases, and did you communicate throughout.
How To Prepare for This Specific Round
Filter the questions below to the most recent reports (past 6-12 months). Questions tagged for this exact round type from this exact company at this exact role level are the highest-signal data available. Older reports may reference questions that have since rotated out of the company's pool.
Practice 4-6 representative problems from this set under timed conditions. The goal is not memorization (companies rotate questions); the goal is to internalize the patterns the interviewer typically reaches for and the depth of follow-up to expect. Reports on LeakCode also tag the typical follow-up depth at this round type, which is the discriminating signal between hire and no-hire calibration.
Phone Screen Round Timing and Format
The Phone Screen round at Dropbox typically runs 45-60 minutes. Use the first 2-3 minutes to clarify requirements; you should never start coding or designing without verifying the input/output format, constraints, and edge cases out loud. Use the next 5-7 minutes to verbalize your approach before writing any code. The middle 20-30 minutes are implementation. Reserve the final 10 minutes for testing with concrete examples and discussing optimization or trade-offs.
Time budget discipline is one of the most reliable senior-vs-junior discriminators in this round. Strong candidates verbalize where they are in their budget out loud ("I've used about 20 minutes, I have 15 minutes left for testing and one optimization"). This signals engineering maturity to the interviewer and creates positive feedback they can capture in writing.
Common Failure Modes in This Round
Reports tagged "no hire" at Dropbox Software Engineer Phone Screen commonly cite: coding silently without verbalizing approach, jumping to implementation before clarifying requirements, missing edge cases (empty input, single element, very large input), producing working code that the candidate cannot refactor when asked, and failing to test their solution with concrete examples before declaring done.
The single most predictive failure mode in 2025-2026 reports: not asking clarifying questions. Interviewers at all FAANG companies are explicitly trained to weight this dimension. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's notes.
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