Databricks is a SaaS business built on top of a bunch of open-source tools, and apparently it’s been going pretty well on the business side of things. In fact, the company claims to be one of the fastest growing enterprise cloud companies ever. Today the company announced a massive $400 million Series F funding round on a hefty $6.2 billion valuation. Today’s funding brings the total raised to almost a $900 million.

Andreessen Horowitz’s Late Stage Venture Fund led the round with new investors BlackRock, Inc., T. Rowe Price Associates, Inc. and Tiger Global Management also participating. The institutional investors are particularly interesting here because as a late-stage startup, Databricks likely has its eye on a future IPO, and having those investors on board already could give them a head start.

CEO Ali Ghodsi was coy when it came to the IPO, but it sure sounded like that’s a direction he wants to go. “We are one of the fastest growing cloud enterprise software companies on record, which means we have a lot of access to capital as this fundraise shows. The revenue is growing gangbusters, and the brand is also really well known. So an IPO is not something that we’re optimizing for, but it’s something that’s definitely going to happen down the line in the not-too-distant future,” Ghodsi told TechCrunch.

The company announced as of Q3 it’s on a $200 million run rate, and it has a platform that consists of four products, all built on foundational open source: Delta Lake, an open-source data lake product; MLflow, an open-source project that helps data teams operationalize machine learning; Koalas, which creates a single machine framework for Spark and Pandos, greatly simplifying working with the two tools; and, finally, Spark, the open-source analytics engine.

You can download the open-source version of all of these tools for free, but they are not easy to use or manage. The way that Databricks makes money is by offering each of these tools in the form of Software as a Service. They handle all of the management headaches associated with using these tools and they charge you a subscription price.

It’s a model that seems to be working, as the company is growing like crazy. It raised $250 million just last February on a $2.75 billion valuation. Apparently the investors saw room for a lot more growth in the intervening six months, as today’s $6.2 billion valuation shows.