Application container firm Docker is staffing up, having brought on new talent to further its security and networking development efforts.

On Tuesday, Diogo Mónica and Nathan McCauley, two former engineers for mobile payments outfit Square, jointly blogged that they had joined Docker to lead its security engineering.

"We've built, managed and secured distributed systems at scale, and now with Docker we can take what we've learned and build security directly into the distributed application platform," the pair wrote.

They may have their work cut out for them. Docker's popularity exploded over the past year, but it was also stung by multiple serious security vulnerabilities that called to question its fitness as mission-critical enterprise infrastructure technology.

Alex Polvi, CEO of CoreOS, which ships Docker as a key component of its cloudy Linux distro, went as far as to describe Docker's security model as "broken" and said his company would develop alternative software. And even Gartner, which is otherwise bullish on Docker, said Docker containers "disappoint when it comes to secure administration and management."

Mónica and McCauley said they are "embedding themselves" into the Docker engineering team and would soon begin a series of blog posts on infrastructure security best practices and container security in particular.

Docker's staffing spree didn't stop there, though. On Wednesday it announced that it had acquired software-defined networking (SDN) startup Socketplane for an undisclosed sum.

Palo Alto, California-based Socketplane, which was founded in the fourth quarter of 2014, described itself as a company comprised of veterans of Cisco, Dell, HP, OpenDaylight, and Red Hat that was working on providing a native SDN solution for Docker. Docker has now brought that expertise in-house.

"Our explicit focus is to lead the collaboration around a rich set of APIs that will empower [Docker] partners to create enterprise-class networking solutions that will further drive the adoption of multi-container, multi-host distributed applications," the Socketplane team wrote in a blog post.

The moves come a month after Docker announced a reshuffle of its top brass in which it divided the project's leadership between a chief architect, chief maintainer, and chief operator.

Docker is also working to reorganize the project's developers around specific subsystems – such as security, networking, storage, and so on – each with its own maintainer. Speaking at the DockerCon Europe conference in Amsterdam in December, Docker CTO and cofounder Solomon Hykes said the idea is to give maintainers a greater sense of ownership over problem areas, rather than have the same people maintain lots of different subsystems.

"If the breakdown is well done, then you have a situation where I wake up in the morning [as a subsystem maintainer] and what I worry about is at human scale," Hykes said. "I don't have to constantly hold the state of everything in my brain, because it's too big now. It's not possible."

Expect Docker to announce more new faces as the year progresses. The company secured a $40m round of funding led by Sequoia Capital in September 2014, which reportedly gave it a total valuation of $400m. ®