Databricks interview questions
Control plane vs data plane, compute types, Unity Catalog, Delta, medallion, DLT, and Photon.
30 questions
Beginner
Control plane vs data plane, Delta basics, and bronze / silver / gold.
Senior
Unity Catalog grants, MERGE file rewrites, OPTIMIZE, Photon fallbacks.
Scenarios
Workspace vs VPC, job-cluster bills, small-file MERGE, DLT expectations.
By topic
Each topic has the lesson and the simulator alongside the questions.
Databricks Architecture
Control plane vs data plane: workspace in Databricks SaaS, clusters and files in your cloud.
Compute types
All-purpose clusters, job clusters that terminate, and SQL warehouses for BI.
Unity Catalog
Three-level namespace, governed storage, and how permissions attach to catalogs, schemas, and tables.
Delta Lake
ACID transactions on object storage: the _delta_log, Parquet data files, time travel, and OPTIMIZE.
Medallion Architecture
Bronze keeps the raw files. Silver is typed and joined. Gold is the metric table BI queries.
Delta MERGE
Upserts a change set into Delta by rewriting only the files the join key touches.
OPTIMIZE & Clustering
Compact tiny files, Z-ORDER for skipping, and liquid clustering on write.
Auto Loader
Incremental ingest from object storage with notifications, checkpoint, and schema evolution.
Delta Live Tables
Declare medallion tables and expectations. DLT infers the graph and stops downstream on failure.
Photon
Native vectorized engine for eligible operators — and the UDF fallback that cancels it.