Marketplace / mobility
Uber interview themes
What people report studying for — not a take-home dump. Last editorial update 2026-07-08.
Rounds you should expect
Design
Trip fact grain. How a streaming count and a nightly batch must reconcile.
SQL
Sessionize or gap events. Event time vs processing time after an outage.
ML features
Point-in-time joins. A backtest that leaked the future.
Recently added questions
2026-09-08 · Point-in-time joins
Your backtest looks perfect. The production model is worse. What join did you write?
A calendar merge that used future labels. Point-in-time is merge_asof (or a warehouse ASOF), not merge on date. Leakage is a join bug.
From the question bank
medium · SQL · SQL
Running total of daily revenue. Why is SUM(SUM(amount)) OVER (...) valid?
Practice →medium · SQL · SQL
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Practice →medium · Warehouse · Snowflake
COPY INTO failed halfway. Is the target table half-loaded?
Practice →medium · Data modeling · dbt
You need yesterday’s incremental plus a 3-day lookback for late CDC. How do you not rebuild the month?
Practice →easy · Orchestration · Airflow
TaskFlow vs operators. When do you still write a classic Operator?
Practice →medium · Orchestration · Airflow
You need a backfill of 400 days. How do you not strand the 08:00 DAG?
Practice →easy · Warehouse · Databricks
A shuffle-heavy join OOMs the worker. Name three levers before you “just scale the cluster.”
Practice →easy · Streaming · Kafka
Why can two consumers in the same group not share one partition?
Practice →easy · Streaming · Kafka
max.poll.interval vs a slow sink.
Practice →hard · Streaming · Kafka
linger.ms and batch.size — what are you trading?
Practice →hard · Streaming · Kafka
acks=all and a producer still duplicates. How?
Practice →easy · Coding · Spark
Narrow vs wide transformation. Why does that decide runtime?
Practice →