Data Engineer Coding & Algorithms Interview Questions
Practice 53 real Coding & Algorithms interview questions for Data Engineer roles. From companies including Meta, Bytedance, Point72, Stripe, Amazon.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Generate All Valid Combinations of Balanced Parentheses
Generate All Valid Combinations of Balanced Parentheses Given an integer n representing the number of pairs of parentheses, generate all distinct stri...
Implement two string utility functions
Implement the following Python functions: 1. number_of_character(string, char) - Return the number of times character char appears in string. - ...
Implement phrase search and JSON path
The coding rounds included two concrete implementation tasks: 1. In-memory document phrase search - You are given a list of documents, each represe...
Implement most_frequent_key without using max()
Problem (Python OOP) You are given two classes. Parent precomputes frequency counts of items (as strings) from an input list. `python class Parent: ...
Solve SQL and Python coding tasks
You are given a small library system with the following relational schema and several Python data-processing tasks. Answer the SQL questions and imple...
Solve two interval array problems
You are given two interval-based tasks from a technical screen for a data engineering role. 1. Merge overlapping intervals - Input: an array of int...
Maximize watch time under adjacency constraint
You are given a sequence of videos in a feed. - Input: - An integer array duration[1..n], where duration[i] is the length of video i in seconds. -...
Find Top Creators and Login Streaks
Solve the following two interview-style tasks. Task 1: Top creators by likes You are given a list of like events for a business-facing creator platfor...
Write SQL for session analytics
You are given two tables for an e-commerce product. Tables 1) shops A shop dimension table that contains duplicate rows for the same shop_id. Columns:...
Count islands using BFS without modifying grid
You are given an m x n binary grid grid where: - 1 represents land - 0 represents water - Islands are groups of horizontally or vertically adjacent la...
Compute User Login Streaks
Given a table user_login_log with the following columns: - user_id: the user identifier - login_date: the calendar date of a login event A user may ha...
Aggregate user logs into 30-minute sessions
You are given a CSV file with columns: user_id | log_datetime | topic Example input rows (already in time order for the same user): - 001 | 2025-03-01...
Compute transaction fees from a CSV string
You are given a CSV string representing a list of payment transactions. Write a function that parses the CSV and returns a CSV string with the total p...
Write SQL for car rental utilization by city
SQL / Data Query Prompt (Car Rental) You are given four tables: user - user_id location - location_id - city car - car_id - car_size (e.g., compact, m...
Implement Portfolio Trading Optimizer
You are given an array prices, where prices[i] is the price of one stock on day i. You may perform multiple buy/sell transactions over the period, but...
Implement a stack supporting max and popMax
Design a data structure that behaves like a stack but also supports retrieving and removing the current maximum value. Implement a class MaxStack with...
Write SQL and merge linked lists
The technical interview included two coding-style tasks: a SQL analytics query and merging two sorted linked lists. Constraints & Assumptions - For SQ...
Generate All Well-Formed Parenthesis Strings
A string of parentheses is called well-formed if every opening bracket ( has a matching closing bracket ) and the brackets are correctly nested. For e...
Implement a Weighted Eviction Cache
Design an in-memory cache whose capacity is limited by total weight rather than by the number of entries. Each entry has: - a key - a value - a positi...
Design a scalable URL shortener
Design a highly scalable URL shortening service, similar to Bitly or TinyURL. The service converts long URLs into short links and redirects short-code...