Dropbox Software Engineer Onsite Coding Questions
16+ questions from real Dropbox Software Engineer Onsite Coding rounds, reported by candidates who interviewed there.
What does the Dropbox Onsite Coding round test?
The Dropbox onsite coding round is the core technical evaluation. Software Engineer candidates typically see 2-3 algorithm and data structure problems. Problems range from medium to hard difficulty, and interviewers evaluate both correctness and code quality.
Top Topics in This Round
Dropbox Software Engineer Onsite Coding Questions
GupShup | SDE2 | Bangalore
Status: 1year 9 months experience Position: SDE2 at GupShup Location: Bangalore Date: May 2020 Was directly called by recruiter, did not apply anywhere. 1st Round on Hackerearth with Interviewer(Team Lead) (1 hour): - Algorithm question...
#135 Candy
LeetCode #135: Candy. Difficulty: Hard. Topics: Array, Greedy. Asked at Dropbox in the last 6 months.
## Problem: Worker Registration Payroll Calculation Given a list of worker “registration / clock-in” events, compute each worker’s payable wages according to the rules described in the prompt. Event
## Problem: Double Circuit Breaker Implement a "double circuit breaker" component for making calls across multiple backend servers and handling failures. ### Setup - There are multiple backend serve
## Problem: Event Logger Design and implement an event logger that appends events to a durable log. ### Requirements - Support **appending events** to the log. - Support writing in-memory events to
You are given a set of candidate words for a Hangman-like game, but the opponent can **adaptively change the secret word** after each guess as long as it remains consistent with the current board stat
Implement a **thread-safe** Token Bucket rate limiter. ### Background Tokens are refilled into the bucket at a fixed rate up to a maximum capacity. A request must consume tokens to pass. ### Require
Implement an in-memory Key-Value store with a clear API. ### Requirements - Support the basic operations: - `put(key, value)`: insert/overwrite - `get(key)`: return the value; return null/error i
Word Game
### Question Description Implement a word guessing game: - Two players, one selects a word, and the other guesses letters. - For each guess, if the letter is in the word, it's a hit and reveal its p
File Crawler
### Question Description Implement a File Crawler: 1. Implement an API that, given a file path, returns all the files in that path. 2. Discuss how to scale the function in step 1 to handle larger di
Word Guessing Feedback
Given a dictionary, a secret word, and a guessed word, your task is to provide feedback based on these inputs. The feedback rule is as follows: - For each letter, if it exists in the same position in
### Problem Description Given a file system represented as a `List<List<string>> folders` and a `HashSet<string> accesses`, implement a function `HasAccess(string folder)` to determine if a user has
Design a program for asynchronous file processing. The program should be able to read files from a given directory and perform specific processing operations on each file after reading. The implementa
Hangman Optimal Strategy
Design a program to play a hangman game. In this game, there are two players; Player 1 guesses letters and Player 2 chooses a word. If both players use optimal strategies, design an algorithm that wil
Implement SnapshotSet
Implement a generic class `SnapshotSet<T>` which supports the following operations: 1. `add(T element)`: Adds an element to the set. 2. `remove(T element)`: Removes an element from the set. 3. `conta
Given a grid with a starting point at (0, 0) and an endpoint at (n-1, m-1). There are four types of walking methods A, B, C, D, each with a fixed time and cost per cell. Find the shortest time path fr
What to Expect in the Dropbox Onsite Coding Round
The Dropbox Software Engineer Onsite Coding round has a specific calibration purpose distinct from other rounds in the loop. Across 16+ 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 Onsite Coding round at Dropbox show recurring patterns in difficulty and topic distribution. The Onsite Coding 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.
Onsite Coding Round Timing and Format
The Onsite Coding 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 Onsite Coding 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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