PySpark Basics Core concepts: RDD, DataFrame, Transformations vs Actions. Common functions: map, flatMap, filter, groupBy, join, withColumn, select, agg. Spark Architecture: Driver, Executors, Cluster Manager. Optimizations: Catalyst Optimizer, DAG, RDD Lineage, Broadcast join. Partitioning: Why partitions matter, repartition vs coalesce. 🔹 SQL Basics Joins (inner, left, right, full, self join). Group By / Aggregations (SUM, COUNT, AVG). Window functions (ROW_NUMBER, RANK, PARTITION BY). Subqueries (scalar vs correlated). CTE (WITH clause).

First we had an OA round followed by 2 technical interviews. The OA was pretty decent whereas of the interview rounds 1st was more on technical understanding heavy while second focused around application and building capabalities.