Problems

18 problems for Data Engineer. Read any of them; sign in to code, run and submit.

Count word frequenciesStrings · Dictionaries~8 minBeginner
Flatten nested batchesLists and tuples · Loops and control flow~5 minBeginner
Leaderboard top NSorting · Lists and tuples~7 minBeginner
Running averageLoops and control flow · Statistics~6 minBeginner
Split work into batchesLists and tuples · Loops and control flow~5 minBeginner
Transpose a metrics tableLists and tuples~5 minBeginner
Group-by aggregationSQL patterns in Python · ETL pipelines · Dictionaries~12 minEasy
Keep the latest event per IDDictionaries · ETL pipelines~10 minEasy
Parse a CSV export into typed recordsETL pipelines · Parsing text~12 minEasy
Size S3 prefixesAWS SDK (Boto3-style) · Dictionaries · Strings~10 minEasy
Build a lazy generator pipelineGenerators and laziness · Time and space complexity~20 minMedium
Chunk documents with overlap for RAGRetrieval-augmented generation · Lists and tuples · LLM integration~15 minMedium
Clean a JSON Lines exportETL pipelines · JSON · Validation and schemas~20 minMedium
Most frequent errors in a streamHeaps · Hashing · Generators and laziness~15 minMedium
Scale features for a modelStatistics · Vectors and embeddings · Lists and tuples~15 minMedium
Async worker pool with retriesasyncio · Retries and backoff · Threads and concurrency~30 minHard
Window functions in PythonSQL patterns in Python · Sorting · ETL pipelines~30 minHard
Exactly-once effects over at-least-once deliverySimulation and state machines · Hashing · ETL pipelines~45 minExpert