PySpark’s Arrow-based Python UDFs open the door to dramatically faster data processing by avoiding expensive serialization overhead. At the same time, Polars, a high-performance DataFrame library built on Rust, offers zero-copy interoperability with Apache Arrow. This talk shows how combining these two technologies unlocks new performance gains: writing Arrow UDFs with Polars in PySpark can deliver performance speedups compared to Python UDFs. Attendees will learn how Arrow UDFs work in PySpark, how it can be used with other data processing libraries, and how to apply this approach to real-world Spark pipelines for faster, more efficient workloads.