An open-source composable
execution engine for data systems
What is Velox?
Velox is a high-performance, open-source execution engine designed for flexibility and reuse. Distributed as a C++ library, it offers modular, composable components that power a wide range of data processing systems from batch and interactive queries to streaming and AI/ML workloads.
The Velox Ecosystem
Velox powers a growing ecosystem of open-source projects, from Spark acceleration with Apache Gluten to next-gen query engines like Presto C++. It’s also the foundation for ongoing work in hardware-accelerated execution.
Apache Gluten
An accelerator for Apache Spark that integrates Velox for native execution.
Learn More →Key Features
Efficiency
Democratizes runtime optimizations previously only implemented in individual engines.
Consistency
By leveraging the same execution library, compute engines can expose the exact same functions, data types, and semantics to their users.
Reusability
Features and runtime optimizations available in Velox are developed and maintained once, reducing engineering duplication and promoting reusability.
The Velox Community
Latest Community News
3.7k GitHub Stars
330+ Contributors
5k+ CommitsVeloxCon 2026
Join us at Meta HQ in the Bay Area, April 29-30 for in-person VeloxCon.
April 2026BlogThe hidden traps of regex in LIKE and split
Both LIKE and Spark's split can silently produce wrong results when used with column values instead of constants.
March 2026Blogvelox::StringView API Changes and Best Practices
This post describes in more detail how Velox handles columns of strings.
February 2026BlogTask Barrier: Efficient Task Reuse and Streaming Checkpoints in Velox
How Velox Task Barriers provide a synchronization mechanism.
January 2026BlogWhy Sort is row-based in Velox — A Quantitative Assessment
Rationale behind this design decision and provide experimental evidence for its implementation.
December 2025EventVeloxCon China 2025
Join us in Beijing on December 13 for our first community event in China.
December 2025BlogMulti-Round Lazy Start Merge
The latest Velox update introduces a multi-round spill merge with lazy-start activation.
November 2025BlogEnabling Shared Library Builds in Velox
Learn how we unblocked shared library builds in Velox.
November 2025BlogVelox switches to C++20 standard
Going forward Velox is looking to enhance the codebase by making use of newer compiler functionalities.
August 2025BlogExtending Velox – GPU Acceleration with cuDF
This post describes the design principles and software components for extending Velox with hardware acceleration using NVIDIA's cuDF.
July 2025BlogSEGFAULT due to Dependency Update
How upgrading Folly and Facebook Thrift revealed a surprising issue with coroutine compile flags and vtable structures.
July 2025BlogVelox Primer: Part 3
Diving deeper into Velox internals and optimization strategies.
May 2025EventVeloxCon 2025
Sessions from VeloxCon are now available on-demand on our YouTube channel.
April 2025BlogVelox Primer: Part 2
Exploring modular execution and system reuse with Velox.
March 2025BlogVelox Primer: Part 1
Introduction to Velox and why composable engines matter.
February 2025BlogVelox Query Tracing
More about Velox query tracing including how it works, its framework, and future plans.
December 2024