---
title: "UDF"
description: "1 posts about UDF, summarised, each linking to the original."
---

# UDF
> 1 posts about UDF, summarised, each linking to the original.

## Articles

### [How to Rewrite Apache Spark UDFs for GPU Acceleration with AI Agents](https://yomu.fyi/post/how-to-rewrite-apache-spark-udfs-for-gpu-acceleration-with-ai-agents.md)
- Company: [NVIDIA](https://yomu.fyi/company/nvidia-developer-blog.md)
- Author: Elizabeth Goodman
- Published: Oct 13, 2026
- Type: Tutorial

User-defined functions (UDFs) in Apache Spark break the declarative abstraction, forcing GPU-accelerated pipelines to fall back to CPU execution and incur data transfer overhead. NVIDIA cuDF addresses this with GPU parallelism, but UDFs remain a bottleneck due to their opaque code. The post describes three approaches to rewrite UDFs into GPU-accelerable forms: SQL expressions, the RapidsUDF interface using cuDF columnar operations, or custom CUDA kernels via JNI. The cuDF skills for Apache Spark automate this process with four agent-guided feedback loops for testing, conversion, benchmarking, and optimization, providing a project template and best practices. A production deployment converted over 30 UDFs, achieving a 22x speedup on a 600-billion-row workload, reducing operator time from 274.55 to 12.78 hours.