Vendor
Databricks interview themes
What people report studying for — not a take-home dump. Last editorial update 2026-08-05.
Rounds you should expect
Lakehouse
What _delta_log does on a failed write. OPTIMIZE vs VACUUM. Liquid clustering vs ZORDER.
Governance
catalog.schema.table, grants, and why path-based tables have no lineage.
Recently added questions
2026-07-28 · VACUUM vs Time Travel
Someone ran VACUUM 0 HOURS on a gold table. What is actually broken?
In-flight readers and every snapshot older than now. VACUUM deletes files. OPTIMIZE does not. Restore is gone if the files are gone.
From the question bank
hard · SQL · SQL
NULL = NULL is unknown. How does that bite a MERGE or an anti-join?
Practice →medium · SQL · SQL
QUALIFY vs a CTE for window filters — when do you use each?
Practice →easy · SQL · SQL
FILTER (WHERE status = 'paid') on an aggregate vs a CASE. Why mention it?
Practice →medium · Data modeling · dbt
ref() vs source() — why does the distinction matter in an incident?
Practice →medium · Data modeling · dbt
Who owns grants after dbt build?
Practice →easy · Data modeling · dbt
A package from dbt Hub pins an old adapter. How do you not freeze upgrades?
Practice →hard · Orchestration · Airflow
data_interval_end vs execution_date. Which one do you use for a daily partition?
Practice →hard · Orchestration · Airflow
setup/teardown vs a hope that the cluster terminates.
Practice →medium · Orchestration · Airflow
deferrable sensors vs poking every 30s. What did you free?
Practice →easy · Warehouse · Databricks
When do you pick Delta on Databricks versus Iceberg on a shared lake?
Practice →medium · Warehouse · Databricks
OPTIMIZE and ZORDER versus Liquid Clustering. What do you actually run weekly?
Practice →easy · Warehouse · Databricks
Unity Catalog vs Hive metastore. Why do interviewers care in 2026?
Practice →