Docker acquires AtomicJar, a testing startup that raised $25M in January

AtomicJar was seemingly a high-flying early-stage startup with a hefty (by today’s standards) $25 million Series A last January. It was building a commercial container testing platform, based on a popular open source project — always a nice combination. It would seem it was time to find product-market fit and take off, but instead the startup decided to combine forces with Docker, the company that invented the notion of containers.

Today, Docker announced it was acquiring AtomicJar and making the 19 employees part of its new testing division. While the two companies didn’t discuss the purchase price, it was enough to take a well-capitalized startup with lots of potential off the market.

Docker CEO Scott Johnston said that the company has been building a comprehensive set of build, test and deploy services on the Docker platform aimed at developers, working on projects before they go into production. By acquiring AtomicJar, the company is essentially buying the testing part of this equation.

It didn’t hurt that the startup was built on top of Docker, or that it was one of the 10 most popular applications in the Docker marketplace. “​​Testcontainers is consistently in the top 10 as measured by pulls or downloads with millions of pulls a month, as well as [hundreds of thousands of] unique IP addresses,” Johnston told TechCrunch. That adds up to over 600,000 monthly unique IP addresses, pulling Testcontainers millions of times every month.

What exactly is Docker getting? As AtomicJar co-founder Sergei Egorov told TechCrunch at the time of the Series A funding, “a big testing issue for developers is that they have been using a representation of the testing components, rather than the actual software, and they often lacked confidence that these tests were actually reproducing what would happen in a live environment. Testcontainers changed that by testing against real versions of the dependent software pieces.”

Egorov said that he was not necessarily looking to sell the company, and that his investors generally encourage companies at his stage to keep building, but this was a good fit combined with a good offer and he decided to move forward with it.

“The year and market were obviously challenging, but not more challenging than for the rest of the industry, and we were well funded to continue building if we wished to, but the shorter path to liquidity combined with a strong product and cultural alignment between Docker and AtomicJar made us believe that now is the right moment for us to join forces,” Egorov told TechCrunch.

Ed Sim, managing partner at Boldstart, an early investor in AtomicJar, says while he usually encourages founders to stay in it for the long haul, his firm gets in early, even before the company is incorporated, so it’s for an attractive price and the decision to sell or not always lies with the founders.

“If the founders believe this is a good time to join forces with another company, then we’re more than happy to roll through with the process, and more likely than not, given where we are on the cap table, we’re going to do quite well, along with the founders,” he said.

Sim said in the case of AtomicJar, he and the Boldstart team were thrilled by the sale, and he sees Docker getting itself a solid company. “I gotta tell you, we’re all pumped up. The company barely even spent the A round. It has a lean team with only 19 people. So this is a lean, mean efficient team that has a crazy open source traction right now,” he said.

AtomicJar co-founder Richard North created the original Testcontainers open source project in 2015. He and Egorov connected in 2021 to start building the commercial company on top of the open source project, which includes users like Uber, Netflix, Spotify and Capital One. The company raised a total of $29 million before today’s acquisition.