Data platform with ingestion and governed accessSystem designDesign a system that ingests large-scale data, processes it, and serves stakeholders with different access needs and sensitivities.
Last asked Sep 2026
#data engineering
+1Web-scale crawl cleaning for pretraining dataSystem designDesign a staged batch pipeline that turns raw web crawl into a deduplicated, quality-filtered, decontaminated pretraining corpus on a fixed cluster and deadline. Reported on…Last asked Mar 2026
Design data pipelines for a short-video appSystem designDesign the data engineering behind a large short-video app: collecting events from clients, streaming and batch processing, the warehouse and data models that analysts and…Last asked Jan 2026
Top three categories by total scoreCodingYou get a list of (category, score) tuples. Add up the score of each category and return the best total you can get from at most three categories (the three highest totals)…Last asked Dec 2025- Data model for feed posts and sharesSystem designModel the data behind a social feed where people create posts and share other people's posts. Name the entities (users, posts, shares and so on), design the fact and dimension…Last asked Dec 2025
- Car rental utilization by city (SQL)CodingGiven tables of rental cars and their rentals, write SQL that reports utilization per city: how much of the available fleet time in each city was actually rented over a period…Last asked Dec 2025
- Library database SQL: unreturned copies, top books and referral gapsCodingA library schema has tables for books, copies, members, checkouts, reservations and authors. Write the queries: 1. How many copies are in good condition and not yet returned?…Last asked Nov 2025
- Design tables and metrics for product event dataSystem designFor a product feature, define the metrics that show whether it is healthy, then design the event and summary tables that compute them: grain, keys, dimensions, and how the tables…Last asked Sep 2025
- Customers who rented in two consecutive weeks (SQL)CodingAmong customers who made purchases in two consecutive full weeks of 2024, return the customer with the most copies rented in the first of those two weeks. Expect to extract the…Last asked Sep 2025
- Validate checkout and return logsCodingGiven a log of events per book, each a checkout or a return (a true/false flag), check that every book's events alternate correctly: a book must be checked out before it can be…Last asked Sep 2025
- Count active follow connections in SQLCodingA table records follow and unfollow events between users over time. Write SQL that returns the current number of active follow connections, taking each pair's latest event into…Last asked Aug 2025
- Recommend accounts your followees followCodingGiven a dictionary from each user to the people they follow, for example {A: B, C, B: C, D, C: E}, return for a user every account followed by the people they follow that they…Last asked Aug 2025
- Carpool ride metrics in SQLCodingFor a ride-sharing product that lets riders share a car, write SQL over ride and request tables for a series of metrics, such as completed shared rides per day and averages per…Last asked Aug 2025
- Cumulative user metrics with a full outer joinCodingMaintain a cumulative table of per-user metrics day by day: combine yesterday's cumulative snapshot with today's activity using a full outer join, so users with no activity today…Last asked Aug 2025
- Top three items per category in SQLCodingFor content in many categories, return the top three items in each category by an engagement measure, handling ties deliberately. Use a ranking window function partitioned by…Last asked Aug 2025
Diagnose a data pipeline's quality and performance problemsBehavioralAsked in a hiring-manager conversation for a solutions architect role: how do you diagnose a data pipeline whose output has quality problems, or whose runs have become slow? Walk…Last asked Jul 2025- Design batch and streaming ETL pipelinesSystem designA data engineering onsite round on pipelines: design how product events are ingested, cleaned and aggregated into tables that analysts use, first as daily batch jobs and then as…Last asked Jul 2025
Walk through a dashboard you built and improvedBehavioralDescribe a dashboard you built: who used it, where the data came from, the tools you used, how you found problems in it or in the data, and what you changed. Expect follow-ups on…Last asked Mar 2025