Practice Topics
- Aggregation — 33 challenges
- DataFrame Basics — 4 challenges
- DataFrame Operations — 5 challenges
- Date Functions — 3 challenges
- Deduplication with ROW_NUMBER — 3 challenges
- Filtering — 3 challenges
- GroupBy Aggregations — 3 challenges
- Joins — 34 challenges
- Window Functions — 74 challenges
More challenges
Individual problems that do not yet belong to a topic with enough siblings to justify its own page.
- Calculate DAU, WAU, MAU for an E-commerce Platform — Hard · SQL
- Complex JSON Transformation for Nested Metrics — Hard · PYTHON
- Count Word Occurrences in a List — Easy · PYTHON
- Current and Previous Address Tracking with SCD Type 2 — Medium · SQL
- Deduplicate and Aggregate User Actions with Latest Session — Hard · PYSPARK
- Detect Anomalies in Transaction Batches — Hard · PYTHON
- Extract Error Codes from Log Strings — Medium · PYTHON
- Find Employees Who Earn More Than Their Department Average — Medium · SQL
- Find the Second Largest Number — Easy · PYTHON
- Flatten Nested JSON Structure — Easy · PYTHON
- Handle Data Skew from High-Frequency Vehicles (PySpark) — Hard · PYSPARK
- Identifying Users with Purchase Frequency Spikes — Hard · SQL
- Implement SCD Type 2 for Customer Data with Delta Lake — Easy · PYSPARK
- Incremental Load with CDC and Latest Update Filtering — Medium · PYSPARK
- Monthly Sales Pivot by Product Type — Hard · SQL
- Optimize Average Rating Calculation for Products — Medium · PYSPARK
- Optimize Join Operation Using Broadcast in AQE — Hard · PYSPARK
- Optimize Small DataFrame Join with Broadcast — Easy · PYSPARK
- Optimize the 100M-Row Join — Hard · PYSPARK
- Parse Apache Logs with Regex — Medium · PYSPARK
- Pivot Sales Data to Show Monthly Totals by Product — Easy · PYSPARK
- Quarterly Sales Pivot by Product — Medium · SQL
- Reverse Words in a Sentence — Easy · PYTHON
- Second Highest Salary — Easy · SQL
- Sum of Even Numbers — Easy · PYTHON
- Sum of Values by Key — Easy · PYTHON
- Top K Frequent Elements in a Stream — Medium · PYTHON
- Total Sales per Region using CTEs — Easy · SQL
- Validate Unique User IDs — Easy · PYTHON
- Word Frequency Counter — Medium · PYTHON