Real Interview Questions

You need to pull 200 million rows from a source JDBC system into Databricks. The current PySpark job uses a single partition and exhausts the driver. How would you redesign the read for parallelism (choose a partitionColumn, set lowerBound/upperBound/numPartitions, handle nulls/outliers, tune fetch size) and ensure the ingest is idempotent before writing to Bronze?

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Pyspark Jdbc Databricks

🟡 Medium Coding Mid Asked 1× May 2026

Your Databricks jobs were migrated to Unity Catalog last week. A nightly Silver write is failing because the storage credential has rotated, and you cannot change IAM roles tonight. How do you restore the write within the same window, considering Unity Catalog grants on the storage credential, external location, object ownership on `catalog.schema.table`, and job cluster access mode, while keeping auditability intact?

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Unity Catalog Databricks Iam

🔴 Hard Debugging Senior Asked 1× May 2026

You are orchestrating a 5‑task lakehouse workflow where Task A discovers a partition path (e.g., s3://raw/yyyyymmdd=20231015) that downstream tasks must use. Finance wants ephemeral, policy‑restricted compute and parallel fan‑out where possible. Which Databricks pattern best fits?

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Databricks Lakehouse Workflow Job Clusters

🟡 Medium Conceptual Junior Asked 1× May 2026

Your team wants repeatable library code for transformations across jobs and clusters. What packaging and deployment approach is most maintainable on Databricks?

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Databricks Python Packaging Libraries Devops

🟡 Medium Conceptual Mid Asked 1× May 2026

A Bronze-to-Silver pipeline requires data quality rules that drop invalid rows while recording metrics for monitoring. Stakeholders want declarative checks and managed lineage without hand‑coding UDF logic. Which option should you choose?

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Delta Live Tables Data Quality Databricks

🟡 Medium Conceptual Junior Asked 1× May 2026

You must implement near‑real‑time ingestion from S3 with schema drift (occasional new columns) while avoiding full listings of the bucket. Badly formed records should land in a quarantine column for triage. Which design is most appropriate on Databricks?

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Streaming Schema Evolution Databricks S3

🟡 Medium Conceptual Junior Asked 1× May 2026

You are orchestrating a 5‑task lakehouse workflow where Task A discovers a partition path (e.g., s3://raw/yyymmdd=) that downstream tasks must use. Finance wants ephemeral, policy‑restricted compute and parallel fan‑out where possible. Which Databricks pattern best fits?

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Databricks Workflows Job Clusters Parallel Execution

🟡 Medium Conceptual Junior Asked 1× May 2026

Can you tell me what vacuum is in Databricks?

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Databricks Delta Lake Data Engineering

🟡 Medium Conceptual Junior Asked 1× Apr 2026

What file format did you use in Databricks?

Databricks Data Formats

🟡 Medium Conceptual Asked 1× Mar 2026