Data Engineer Interview Questions
Practice 140 real Data Engineer interview questions for 2026. Covers companies like Meta, TikTok, Rbcroyalbank, Capital One, and Amazon — real Data Engineer interview questions from actual interviews with detailed solutions to help your interview preparation. Expect the loop to emphasize production-grade SQL, scalable ETL and pipeline design, distributed-processing tooling (Spark/Kafka), data modeling for analytics and OLAP, and data-quality/observability trade-offs alongside behavioral and product-sense conversations tied to metrics. What’s distinctive: hiring teams now prioritize shipping reliable pipelines and diagnosing failures in production over pure algorithmic puzzles, so you’ll be evaluated on writing efficient windowed SQL, designing fault-tolerant pipelines, choosing storage and partitioning strategies, and explaining trade-offs around latency, cost, and observability. To prepare, practice timed SQL and Python exercises, sketch end-to-end pipeline designs with concrete components (Airflow, Kafka, S3/BigQuery/Redshift), rehearse STAR stories about ownership and incident response, and run mock interviews that simulate debugging a broken pipeline under time pressure.

"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."
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...
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', ...
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 ...
Evaluate impact of short videos in feed
Scenario You work on a social app’s main News Feed. The team wants to introduce a short-form video module ("Reels") into the feed. Prompt 1. How would...
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...
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...
Compute shipping cost with tiered pricing
You are building a shipping-cost calculator. Each order contains line items, and shipping rules vary by destination country and product. Assume: - Ord...
Design a Warehouse for Key Metrics
Design a Warehouse Model for Marketplace Analytics You are designing a warehouse model for an e-commerce marketplace with buyers, sellers, orders, ord...
Demonstrate behavioral competencies
Behavioral Interview Prompt: Prepare STAR Stories Context You are preparing for an onsite Behavioral & Leadership interview for a Data Engineer role. ...
Analyze private-account product metrics
Question A social network is building (or refining) a private account feature: any user can set their account to private, in which case only approved ...
Aggregate Netflix metrics in SQL
Question Netflix video-streaming analytics SQL: Write a simple aggregation (e.g., total watch-time per day). Build a cumulative metric: today’s metric...
Design visualizations for streaming metrics
Design a Monitoring and Diagnosis Visualization for a Video-Streaming Metric Context You are building an observability dashboard for a global consumer...
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...
Define and validate product metrics
End-to-End Analytics Design for a New Product Feature Context: You are the data engineer partnering with product, engineering, and data science to lau...
Demonstrate ownership and conflict resolution
Behavioral: 0→1 Data Initiative, Prioritization, and Cross-Functional Leadership Context: Onsite interview for a Data Engineer role. Provide a concise...
Solve Two String Problems
You are asked to solve the following two coding problems: 1. Unique Morse Code Transformations You are given an array of lowercase English words, word...
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...
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...
Write SQL for active follow connections
Table: follow_events(requester_id INT, target_id INT, event STRING CHECK (event IN ('request_follow','follow_success','follow_reject','unfollow')), ev...