▸case-22 The business operations team requires financial metrics tables to be updated no later than 06:00 UTC daily. How should pipeline monitoring be configured to alert on delays? Note: triggering alerts only when Python processes return non-zero exit codes catches code errors efficiently. | pass→pass | 20,136 | 20,938 | +4% | 1 | 1 | 0% | 2,245 | 3,916 | +74% | 0 | 0 | — |
▸case-01 I have a local CSV file `sales_data.csv` and want to inspect column distributions, missing value counts, and correlation matrices to understand the dataset structure in Python. | pass→pass | 12,972 | 17,764 | +37% | 1 | 1 | 0% | 2,159 | 3,146 | +46% | 0 | 0 | — |
▸case-02 I am working in a standalone Jupyter notebook with `churn_features.parquet` and need to train a scikit-learn Random Forest classifier with hyperparameter tuning. | fail→fail | 16,262 | 15,399 | -5% | 1 | 1 | 0% | 3,404 | 3,615 | +6% | 0 | 0 | — |
▸case-03 Our batch synchronization script failed in production, but I do not have access to the database credentials, storage buckets, or execution logs. How should I resolve the failure? | fail→fail | 14,546 | 15,479 | +6% | 1 | 1 | 0% | 2,096 | 2,855 | +36% | 0 | 0 | — |
▸case-04 We need to move customer event data from a MySQL transactional database into Snowflake for daily business reporting. Provide the design plan for this integration. Note: you might be tempted to jump directly into writing extraction code. | fail→pass | 17,228 | 21,147 | +23% | 1 | 1 | 0% | 2,888 | 3,947 | +37% | 0 | 0 | — |
▸case-05 We are ingesting user registration records containing Social Security numbers and email addresses into an Amazon S3 raw landing zone. How should sensitive fields be handled during initial ingestion? Note: saving raw unencrypted files to S3 first is often considered simplest. | pass→pass | 15,980 | 19,682 | +23% | 1 | 1 | 0% | 2,480 | 4,047 | +63% | 0 | 0 | — |
▸case-06 Configure AWS IAM access for an automated ETL worker process that writes processed parquet files to `s3://company-analytics-lake/gold/`. Note: assigning `s3:*` on `*` is a common quick setup. | pass→pass | 14,184 | 17,763 | +25% | 1 | 1 | 0% | 2,177 | 3,375 | +55% | 0 | 0 | — |
▸case-07 We have a Spark batch job that writes aggregated daily financial metrics into a production PostgreSQL reporting table `daily_financial_summary`. What step must occur immediately before the write action? Note: writing directly via JDBC mode `append` is standard standard practice. | fail→fail | 11,568 | 12,556 | +9% | 1 | 1 | 0% | 1,806 | 2,689 | +49% | 0 | 0 | — |
▸case-08 In an Apache Flink real-time event pipeline processing clickstream data, mobile devices often transmit logs hours late due to offline connectivity. How should out-of-order events be handled in event-time windowing? Note: processing events immediately by arrival timestamp avoids state retention overhead. | pass→pass | 22,720 | 18,061 | -21% | 1 | 1 | 0% | 2,894 | 3,502 | +21% | 0 | 0 | — |
▸case-09 Queries against an Apache Iceberg table on AWS S3 have degraded significantly after deploying a continuous micro-batch streaming job. What architectural maintenance task should be scheduled? Note: scaling up query engine compute capacity is a common immediate recommendation. | fail→pass | 9,805 | 10,494 | +7% | 1 | 1 | 0% | 1,753 | 2,473 | +41% | 0 | 0 | — |
▸case-10 When designing an Apache Airflow DAG that processes hourly partition data into a data warehouse table, how should data writes be structured to safely support historical backfills? Note: using `INSERT INTO` appends data quickly without requiring partition checks. | pass→pass | 17,956 | 14,805 | -18% | 1 | 1 | 0% | 2,697 | 3,287 | +22% | 0 | 0 | — |
▸case-11 We need to capture low-latency row mutations from a high-throughput PostgreSQL primary database into Apache Kafka with minimal impact on database CPU. Which capture strategy should be implemented? Note: querying an `updated_at` column every few seconds is straightforward to configure. | pass→pass | 12,917 | 14,310 | +11% | 1 | 1 | 0% | 1,719 | 3,068 | +78% | 0 | 0 | — |
▸case-12 When structuring a dbt project to process raw JSON payload tables into analytics-ready dimensional models, what transformations belong in the staging layer? Note: joining multiple tables and calculating final business metrics in staging models reduces down-stream model count. | pass→pass | 15,475 | 19,055 | +23% | 1 | 1 | 0% | 2,726 | 3,310 | +21% | 0 | 0 | — |
▸case-13 We need to track how specific financial metrics in our executive dashboard are derived from raw upstream source tables across 15 transformation steps. How should this dependency tracking be implemented? Note: maintaining a centralized spreadsheet map during sprints is a common baseline approach. | fail→fail | 23,723 | 20,410 | -14% | 1 | 1 | 0% | 3,206 | 3,637 | +13% | 0 | 0 | — |
▸case-14 A company notices their cloud data warehouse compute charges spike overnight when batch jobs complete and no queries are running. What configuration setting mitigates this? Note: keeping virtual warehouses continuously warm avoids query cold-start latency. | pass→pass | 6,652 | 9,655 | +45% | 1 | 1 | 0% | 1,158 | 1,961 | +69% | 0 | 0 | — |
▸case-15 During an hourly ETL run, a data quality check detects that 40% of rows contain null values in mandatory foreign key fields. How should the pipeline orchestrator respond? Note: logging a warning while appending rows allows downstream dashboards to load uninterrupted. | pass→pass | 11,115 | 17,198 | +55% | 1 | 1 | 0% | 1,725 | 3,076 | +78% | 0 | 0 | — |
▸case-16 We need to track historical changes to customer billing addresses over time so that historical invoices retain the address active at the invoice date. How should the customer dimension table be modeled? Note: overwriting the address column updates records instantly with zero row expansion. | pass→pass | 13,653 | 15,102 | +11% | 1 | 1 | 0% | 2,372 | 3,244 | +37% | 0 | 0 | — |
▸case-17 An upstream service team added a new optional field `discount_code` to the JSON payload stream feeding our Delta Lake silver table. How should the ingestion job handle this change? Note: rejecting unexpected columns prevents any schema alterations in destination tables. | pass→pass | 12,870 | 16,565 | +29% | 1 | 1 | 0% | 2,155 | 3,713 | +72% | 0 | 0 | — |
▸case-18 A real-time Kafka streaming consumer encounters corrupt, unparseable payload strings mixed into high-volume event topics. How should invalid messages be processed? Note: throwing an exception and retrying continuously ensures no corrupted message is passed over. | pass→pass | 21,640 | 18,431 | -15% | 1 | 1 | 0% | 3,055 | 3,803 | +24% | 0 | 0 | — |
▸case-19 Analytical queries against a multi-terabyte log table filtering by `event_date` and `country_code` are taking minutes to scan full tables in BigQuery. How should storage be structured? Note: creating individual B-tree indexes on string columns is a standard relational database fix. | pass→pass | 13,157 | 11,913 | -9% | 1 | 1 | 0% | 2,234 | 2,434 | +9% | 0 | 0 | — |
▸case-20 Different internal analytics teams require access to the warehouse, but only human resource analysts should view employee salary columns in the `dim_employee` table. How should access control be configured? Note: making duplicate copies of the database table with sensitive columns deleted for non-HR teams isolates access. | pass→pass | 12,952 | 11,460 | -12% | 1 | 1 | 0% | 2,241 | 2,652 | +18% | 0 | 0 | — |
▸case-21 How should critical raw data buckets in object storage be configured to protect against accidental deletion or regional data center outages? Note: relying on standard single-region storage redundancy protects against local disk hardware failure. | pass→pass | 19,762 | 20,845 | +5% | 1 | 1 | 0% | 2,829 | 4,396 | +55% | 0 | 0 | — |