The Databricks Certified Associate Developer for Apache Spark 3.0 certification tests your understanding of the Spark DataFrame API. It assesses your ability to use the Spark DataFrame API to perform basic data manipulation tasks within a Spark session. These tasks include manipulating, filtering, dropping, and sorting columns, handling missing data, and combining, reading, and writing DataFrames with schemas. The exam also covers working with UDFs or Spark SQL functions. Additionally, the exam assesses fundamental aspects of Apache Spark architecture, such as execution/deployment mode, execution hierarchy, fault tolerance, and garbage collection.