Container security startup Aqua Security today announced that it has secured a $9 million Series A funding led by Microsoft Ventures. Aqua’s seed investors, TLV Partners and cyber security investor Shlomo Kramer, also participated in this round of funding, bringing the company’s total investment to $13.5 million.

The Aqua Container Security Platform tracks a container’s status throughout its lifecycle and supports containers from Docker, CoreOS, VMware, and no surprise here, Microsoft.

“We are very excited to be working with the Microsoft Ventures team to tackle our next phase of growth,” wrote Aqua CEO Dror Davidoff in a blog post this morning. “Naturally, we will be doing many things around Microsoft initiatives. But on the other hand, we will of course continue to support diverse cloud and container environments, working with the Docker community, the Kubernetes community, and others.”

Since its launch in May 2016, the company has attracted Fortune 500 customers in the financial services, technology, retail, and online services areas. The company says it plans to double its staff by mid-2017.

Separately, Aqua also announced today that Kramer, seed round investor, will join the company’s board of directors bringing experience in security and investing. Kramer is also the co-founder and CEO of Cato Networks.