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Updated weekly · Last refresh Aug 30

Current (NY) Data Engineer Interview Questions

The questions to prepare for a Current (NY) Data Engineer interview. Questions from real interview reports rank first. Updated weekly.

50questions
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1
SQL & Data ManipulationStart here. 13 questions + 2 drills · ~128 min
7-Day Rolling Active UsersMedium
Practice

Compute daily active users and a 7-day rolling average using a CTE, distinct counts, and window functions.

Window FunctionsDate FunctionsRunning TotalsCurrent (NY)
Readable, Logically Sound SQLEasy

Tests writing maintainable SQL with clear logic, naming, and correctness.

JoinsData WranglingCTEsCurrent (NY)
Optimize Query With Data SkewHard

Tests performance tuning strategies for skewed data and large join patterns.

SubqueriesJoinsData WranglingCurrent (NY)
Top Users by Recent Transaction VolumeMedium
Practice
Practice drill

Find the top 3 users by completed transaction volume in the last 30 days using joins and aggregation.

Data Analysisquery optimizationsqlTTier 1 BankRevolutChime
Monthly Sales Trends by CategoryMedium
Practice
Practice drill

Aggregate monthly sales by product category and use LAG to calculate month-over-month changes.

InfrastructureToolsData WranglingTotal Wine & MoreInc.Benjamin Moore
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2
Pipelines36 questions · ~298 min
Design SCD Type 1 and 2Medium

Design and implement SCD Type 1 and Type 2 dimensions with history tracking, idempotent loads, and data quality controls.

slowly changing dimensionsData ModelingBackfillingCurrent (NY)
Choosing Batch vs Real TimeHard

Evaluate when a pipeline should use stream processing versus scheduled batch based on latency, cost, complexity, and data quality needs.

Stream ProcessingBatch ProcessingDependenciesCurrent (NY)
Batch vs Stream Processing Trade-offsMedium

Compare batch and stream processing across latency, complexity, cost, and data quality in a modern analytics pipeline.

InfrastructureStream ProcessingETLCurrent (NY)
Fraud Detection Batch vs StreamingMedium

Design a fraud pipeline that compares batch, streaming, and hybrid architectures for 120K tx/sec with sub-300 ms decisions and reconciled hourly tables.

Stream ProcessingETLBatch ProcessingCurrent (NY)
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3
More topics1 question · ~8 min
Clean Maintainable Python ETL ScriptsEasy

Tests software engineering practices for reliable data extraction and automation.

Hash TablesArraysSortingCurrent (NY)
The finish line: interview-readyComplete all 50 questions plus 2 hands-on drills to finish this plan.