Data Engineer Coding & Algorithms Interview Questions
Practice 55 real Coding & Algorithms interview questions for Data Engineer roles. From companies including Meta, Google, Point72, Stripe, Bytedance.
"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."
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 string problems
You are asked to solve the following two coding problems. 1. Count unique Morse code translations You are given an array of lowercase English w...
Solve SQL and PySpark Data Tasks
This question evaluates proficiency in SQL query design and PySpark DataFrame manipulation, covering aggregation, filtering, joins, time and numeric f...
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...
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...
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 for first share and closest collaborator
You are given event data about users viewing design files. Assume the following tables: - files(file_id, creator_id) - creator_id is a VARCHAR user ...
Write SQL for basic user metrics
You are given a simplified schema for a fictional social app called Nextagram: - users(user_id PK, username, created_at TIMESTAMP) - follows(follower_...
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...
Compute User Login Streaks
This question evaluates SQL proficiency in processing event logs for time-series analysis, encompassing date arithmetic, deduplication of same-day eve...
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...
Find Top Creators and Login Streaks
This question evaluates proficiency in data aggregation, algorithmic optimization for top-k retrieval, and SQL time-series analysis using window funct...
Encode and Rebuild a Binary Tree
Design two functions for a binary tree: - encode(root) -> string - decode(data) -> root Each tree node contains an integer value and has up to two chi...
Write queries for follows and bookings
This question evaluates the ability to manipulate temporal event logs, enforce bidirectional relational integrity, and implement efficient graph and i...
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...
Write Transaction Analytics SQL Queries
You are given a credit-card transaction dataset with the following tables. transactions | column | type | description | |---|---|---| | transaction_id...
Write SQL revenue and anomaly queries
You are given two tables. Table: transactions | Column | Type | Description | |---|---|---| | transaction_id | int | Unique identifier for each transa...
Write SQL using joins and window functions
SQL Coding: Rank within Groups with Joins You are given two tables: accounts - account_id (string) - customer_id (string) - segment (string) — e.g., "...
Write SQL Data Transformation Queries
This question evaluates proficiency in SQL data transformation and aggregation, testing competencies such as monthly-reset running totals, hierarchica...
Implement phrase search and JSON path
This question evaluates the ability to build an inverted index for in-memory exact phrase search and to implement JSON path traversal with wildcard ma...