What do people mean by a PySpark certification?
They almost always mean the Databricks Certified Associate Developer for Apache Spark. PySpark is the Python API of Apache Spark, an open-source project that publishes documentation and no exam. Databricks runs the Spark Developer exam and says all code in it is in Python, which makes it the PySpark credential a recruiter will recognise. Databricks says the exam checks Spark's architecture and the DataFrame API for basic data work: changing columns, filtering, sorting and aggregating rows, handling missing data, reading and writing DataFrames with schemas, and UDFs and Spark SQL functions. It also covers lazy evaluation, shuffles, broadcasting, Structured Streaming, Spark Connect and basic tuning.