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9.6k Questions 505 Companies08.05.2026
Showing 20 results
Role
Meta logo
Meta
Medium
Data Engineer

Write SQL and Python for data prep

Given clickstream events (user_id, event_type, ts, properties) and a users table (user_id, signup_ts, plan), write SQL to compute DAU/WAU/MAU, D1/W1 r...

Data Manipulation (SQL/Python)
1
1
8 people solved
Jul 15, 2025
Meta logo
Meta
Medium
Software Engineer

Evaluate arithmetic expression without parentheses

Evaluate arithmetic expression without parentheses Write evaluate(s: string) to compute the value of an arithmetic expression containing non-negative ...

Coding & Algorithms
3
0
38 people solved
Jul 15, 2025
TikTok logo
TikTok
Medium
Software Engineer

Reconstruct a tree from two traversals

Reconstruct a tree from two traversals Given two arrays representing the preorder and inorder traversals of a binary tree with unique values, reconstr...

Coding & Algorithms
4
0
45 people solved
Jul 15, 2025
TikTok logo
TikTok
Medium
Data Engineer

Debug a Hive insert query

Given a Hive table schema and an incoming table plus an INSERT/SELECT statement meant to inject data, identify why the query fails and provide step-by...

Data Manipulation (SQL/Python)
0
0
5 people solved
Jul 15, 2025
Meta logo
Meta
Hard
Data Scientist

Determine Demand for WhatsApp Group Video-Calls

Determine Demand for WhatsApp Group Video Calls WhatsApp is considering launching group video calls. Assume the feature does not currently exist, but ...

Analytics & Experimentation
70
0
200 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Analyze Recent Post Performance Using SQL Queries

INFO_STREAM_VIEWS +---------+-----------+--------------+----------+------------+ | post_id | viewer_id | relationship | duration | ds | +-----...

Data Manipulation (SQL/Python)
41
1
6 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Business Intelligence Engineer

Find Top Three Books by City in Recent Months

BOOK_SALES +------+--------+------------+------------+ | city | asin | sale_date | units_sold | +------+--------+------------+------------+ | NYC ...

Data Manipulation (SQL/Python)
4
0
20 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Business Intelligence Engineer

Calculate Rolling 7-Day Sum of Answers by Device

ANSWERS +------------+--------+---------+ | date | device | answers | +------------+--------+---------+ | 2019-01-01 | echo | 10 | | 2019...

Data Manipulation (SQL/Python)
11
0
41 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Evaluate Facebook's Restaurant Recommendations Feature Effectiveness

Experiment Design: Restaurant Recommendations in Facebook News Feed Facebook is considering restaurant recommendation units inside News Feed, such as ...

Analytics & Experimentation
12
0
36 people solved
Jul 12, 2025
Pinterest logo
Pinterest
Medium
Data Scientist

Implement LRUCache with O(1) Operations and Thread Safety

Scenario High-traffic API needs constant-time eviction cache. Question Implement an LRUCache supporting get(key) and put(key,val) in O( 1). Describe ...

Coding & Algorithms
16
0
62 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Expected meetings in Room 1 after random assignment

Expected Meetings in Room 1 Conditional on Being Non-empty There are N rooms and k meetings. Each meeting independently chooses a room uniformly at ra...

Analytics & Experimentation
12
0
32 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Data Scientist

Calculate Regional Revenue and Identify Top Customers

Customers | customer_id | name | region | |-------------|-------|--------| | 1 | Alice | East | | 2 | Bob | West | | 3 ...

Data Manipulation (SQL/Python)
9
1
4 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Calculate Average Session Length and Compare App Performance

user_sessions +---------+------------+------------+---------------------+---------------------+ | user_id | session_id | app | session_start ...

Data Manipulation (SQL/Python)
125
0
324 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Business Intelligence Engineer

Identify Unique Unordered City Pairs in Flight Log

FLIGHTS +----------------+---------------+ | departure_city | arrival_city | +----------------+---------------+ | NYC | LAX | | ...

Data Manipulation (SQL/Python)
3
0
2 people solved
Jul 12, 2025
PayPal logo
PayPal
Medium
Data Scientist

Describe Leading Without Authority in Data Management

Behavioral Interview: Leading Without Authority in Data Management You will be assessed on cultural fit and how you operate in ambiguous, messy data e...

Behavioral & Leadership
30
0
75 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Business Intelligence Engineer

Calculate Weekly Event Sums from Daily Counts

EVENT_LOG +------------+------+ | event_date | cnt | +------------+------+ | 2025-05-01 | 17 | | 2025-05-02 | 12 | | 2025-05-08 | 30 | +-------...

Data Manipulation (SQL/Python)
2
0
6 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Calculate Survey Response Rate and Quality Metric in SQL

survey_responses +---------+----------+---------------------+---------------------+-------+ | user_id | survey_id| impression_ts | click_ts ...

Data Manipulation (SQL/Python)
70
0
159 people solved
Jul 12, 2025
Meta logo
Meta
Medium
Data Scientist

Compute Shop Visibility Rate Using SQL and Python

shop_events | event_id | shop_id | user_id | event_type | event_time | | 1 | 101 | 1001 | view | 2023-07-01 10:05:00 | | ...

Data Manipulation (SQL/Python)
73
0
170 people solved
Jul 12, 2025
Amazon logo
Amazon
Medium
Business Intelligence Engineer

Analyze Seller Compliance and Customer Purchase Patterns

SELLER_STATUS +-----------+------------+-----------+ | seller_id | date | status | +-----------+------------+-----------+ | 1 |2019-0...

Data Manipulation (SQL/Python)
5
0
18 people solved
Jul 12, 2025
Citadel logo
Citadel
Medium
Data Scientist

Implement Infinite Fibonacci Generator Using Lazy Evaluation

Scenario Testing understanding of Python lazy evaluation and generators. Question Explain what lazy evaluation means in Python and implement a generat...

Coding & Algorithms
20
0
41 people solved
Jul 12, 2025