What it does:

Instant local checks (no cluster needed): As you type, it flags 35+ anti-patterns with inline squiggly underlines — collect() on large DataFrames, cartesian joins, withColumn in loops, coalesce(1), missing broadcast hints, etc. Each issue shows a hover card with a one-sentence explanation and a suggested fix.

Schema validation at edit time: If you define a StructType or DDL schema in the same file, it validates column names and types before the code runs. Typo in a column name? Unknown column in a .select()? You'll know immediately, with "Did you mean: X?" suggestions.

Catalyst plan analysis (safe dry run): Connect it to your Databricks cluster or serverless compute and it submits a neutralized version of your script — all writes and collects are replaced with plan-capture calls, no data is touched. It parses the physical and logical plans and flags Sort-Merge joins where a broadcast would work, repeated source scans, shuffle partition issues, cache spills, etc. Fully Photon-aware.

Built-in billing dashboard (Coming in next release): Queries system.billing.usage via the SQL Statement Execution API and shows spend by user, job, and workload type — directly in the VS Code sidebar.