The startup behind open source tool Polars raises $21M from Accel

Polars, the Amsterdam-based startup behind the widely used open-source data processing tool of the same name, has raised €18 million (approximately $21 million) in a Series A funding round led by Accel, with participation from Bain Capital Partners and several angel investors.

Interestingly, Polars' creator, Ritchie Vink, didn't initially set out to build a venture-backed company. The project began as a personal experiment during the COVID-19 pandemic, born out of Vink's frustration with the limitations of Pandas, the popular Python data analysis library. Wanting something faster and more efficient, he decided to build a query engine in Rust.

Five years later, Polars has become one of the fastest-growing data processing tools, known for its ability to handle large datasets significantly faster than existing solutions. This performance edge has made it popular among data scientists and engineering teams worldwide.

From Open Source to Scalable Business

While Polars' open-source success fueled investor interest, the Series A was driven by the company's commercial roadmap. Two years after incorporating, Polars launched Polars Cloud, a managed data platform that allows users to run large-scale data queries directly in the cloud.

"In the open source community, the joke is that you can rewrite anything in Rust and it becomes better," said Accel partner Zhenya Loginov, who led the funding round. "The reason that it's a joke is that it's not a real sustainable advantage — you need to do a lot more."

For Vink and co-founder Chiel Peters (former CTO of Xomnia), "doing more" means building complementary products such as Polars Cloud and Polars Distributed. The latter is a distributed query engine designed to handle petabyte-scale workloads, currently available in public beta. According to Vink, much of the newly raised funding will be used to develop Polars Distributed further.

With this technology, Polars is positioning itself as a competitor to Apache Spark, the open source framework whose creators went on to found Databricks.

Closing the Gap Between Pandas and Spark

Before this round, Polars had already raised a $4 million seed round in 2023, led by Bain Capital, following significant traction among Pandas users who required increased speed and scalability. While Pandas remains open source without a commercial product, Polars' evolution into a managed and distributed platform has created a clear path to monetisation.

Despite already surpassing 24 million downloads, Polars' leadership believes the actual value lies in helping users scale seamlessly — from running analytics on a laptop to processing massive datasets across distributed clusters.

Loginov agreed, saying, "If you go into being able to process datasets of any size and complexity, you're solving a lot of challenges for a lot of enterprises. So we felt that the ultimate market is potentially extremely large."

A Growing Role in Enterprise Data Workflows

Polars' technology is already being used in production environments across various industries, including finance, life sciences, and logistics. However, with Polars Cloud and Polars Distributed, the company is now entering a new phase — transitioning from an open-source favourite to a comprehensive enterprise data platform.

For other founders looking to commercialise open source projects, Loginov shared a key takeaway from Vink's journey:

"Polars became successful because it addressed a really big problem — he found a niche where the technology available today is just outdated by a mile. So I would suggest finding a large problem."