Data Engineer Interview Questions
Practice 160 real Data Engineer interview questions for 2026. Covers companies like Meta, TikTok, RBC Royal Bank, and Point72 — real questions from actual interviews with detailed solutions. This collection of Data Engineer interview questions is designed for hands‑on interview preparation: expect live SQL and Python exercises, pipeline design and debugging, and case problems that test data modeling, throughput and latency tradeoffs. What’s distinctive about data engineering interviews is the mix of coding plus systems thinking: interviewers evaluate SQL fluency and data modeling, end‑to‑end pipeline architecture (streaming, Spark, Kafka) and data reliability/observability. Meta, TikTok, RBC Royal Bank, and Point72 are actively hiring for this role and commonly test scalable ETL design, warehouse/schema design and production reliability. To prepare, practice medium‑to‑hard SQL, build a few Spark/streaming exercises, sketch architecture tradeoffs for high‑throughput pipelines, and rehearse concise behavioral stories that show ownership and incident response.
"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."
Return count and renewal percentage of unreturned good copies
Tables: copies(copy_id, condition), checkouts(copy_id, checkout_date, return_date, renewal_count). Write a single SQL query that returns one row with ...
Compute missing letters to form original string
Implement a function that, given two strings original and typed (typed is a misspelled/partial version of original), returns the number of additional ...
Validate alternating checkout/return logs
Given a chronological list of events logs of the form (timestamp, book_id, is_checkout) where is_checkout is True for a checkout and False for a retur...
Compute reservation diff for largest member
Given copies(copy_id, reserved_by_member_id) and members(member_id, referred_by_member_id), find the member with the largest member_id. Return a singl...
Write Postgres string parsing and aggregation query
You are given a PostgreSQL table events(user_id TEXT, raw TEXT) where raw stores pipe-delimited key=value pairs, for example 'user=U1|country=US|ts=20...
Recommend friends-of-friends
Question Given a dictionary such as {A:[B,C], B:[C,D], C:[E]}, return for a user U all people followed by U’s followees but not already followed by U....
Count active follow connections
Question Write SQL to return the current number of active follow connections. Events table columns: user_id, target_id, event_type ('request_follow', ...
Query carpool ride metrics
Question For a ride-sharing product with carpool capability, answer a series of SQL questions (e.g., daily completed pooled rides, average seats utili...
Compute cumulative metrics with full joins
Tables: - daily_metrics(date DATE, content_id STRING, daily_value BIGINT) - cumulative_metrics(date DATE, content_id STRING, cumulative_value BIGINT) ...
Return top-3 content per category
Given a collection of items with fields (content_id, category, rating), implement top_k_by_category(items, k= 3) that returns, for each category, the ...
Recommend two-hop follows in Python
Given a directed "follows" graph as a Python dict[str, list[str]], implement recommend_two_hop(graph, user) that returns the set (or a sorted list) of...
Check carpool trip feasibility
You are given a list of trips where each trip i is (passengers_i, start_i, end_i) with start_i < end_i on a one-dimensional route. A single vehicle wi...
Write SQL for Transactions and Customers
You are given two tables: - customers(customer_id INT PRIMARY KEY, signup_date DATE, region VARCHAR, segment VARCHAR) - transactions(transaction_id IN...
Design visualizations for streaming metrics
Design visualizations for streaming metrics Design a Monitoring and Diagnosis Visualization for a Video-Streaming Metric Context You are building an o...
Write SQL for library analytics
Given a library database, write SQL to answer the following: 1) Count the number of books that are currently not returned (i.e., still checked out) an...
Solve library coding tasks in Python
Solve library coding tasks in Python Implement the following Python tasks: 1) Given a list of (category, points) for books, choose up to 3 books with ...
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...
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...
Explain a SQL query result
Given two tables and a specific SQL query, precisely explain the expected result set: which rows are returned, what each column contains, how joins/fi...
Count Special Index Pairs
Given an integer array nums of length n, count the number of index pairs (i, j) such that: - 0 <= i < j < n - nums[i] * nums[j] is even - j - i is odd...