Container development software provider Docker Inc. said today it’s expanding its testing capabilities with the acquisition of a well-funded startup called AtomicJar Inc.

Neither company disclosed any price, but it seems likely Docker handed over a significant amount considering that AtomicJar had raised $25 million in a Series A funding round in January, bringing its total amount raised to more than $29 million.

The startup is the company behind the open-source Testcontainers project that was launched in 2021 and is used to test software components ahead of their release. AtomicJar’s main offering is an enhanced version of that open-source software, and provides an integrated testing platform that’s used by developers building applications, databases and web frameworks.

With AtomicJar’s platform, developers are said to become more productive, while the software they create is more resilient. In turn, the organizations those developers work for can become more agile.

The Testcontainers Cloud platform can be installed in five minutes and guarantees full consistency in its test results, together with faster execution. By using its service, AtomicJar says engineering teams also get a productivity boost, as it eliminates all hardware and software limitations. It enables developers to test their applications on laptops without worrying about resources, run test suites without scaling up to a workforce, and enhance their efficiency by ensuring consistent results from development to continuous integration.

AtomicJar co-founder Sergei Egorov told TechCrunch that his company solves one of the biggest challenges for developers in software testing. Traditionally, they have always had to test a representation of their software components, as opposed to the software itself.

As a result, there have always been doubts that their tests reproduce what would happen in live environments. Testcontainers does away with these concerns by enabling testing against real versions of the dependent software components.

According to AtomicJar, it has seen significant growth since its launch in 2021. The open-source version of Testcontainers was downloaded more than 200 million times in 2022. It also saw a 100% increase in Docker Hub pulls, from 50 million to 100 million, making it one of the fastest-growing Docker Hub projects that year. The startup boasts notable customers including Netflix Inc., Spotify Technology SA, DoorDash Inc., Uber Technologies Inc., Wise Payments Ltd., Elastic NV, Skyscanner Ltd. and Google LLC.

The addition of AtomicJar’s capabilities could provide a boost to Docker, which sells tools for building, deploying and testing container-based applications. Using Docker, developers can create and test software containers, which host the components of modern applications, on their local machines, and share the code they write with colleagues. It also provides the tools needed to stitch together multiple containers into working applications.

In a blog post, Docker Chief Executive Scott Johnston said the company is looking to provide a full suite of build, test and deploy services through the Docker platform. With the acquisition of AtomicJar, it gains a comprehensive, well-known and ready-made testing suite.

It won’t hurt the company’s plans that Testcontainers was already one of the top 10 most popular applications on the Docker marketplace for third-party developer tools that can integrate with its platform.

Johnston said one of the most exciting things about the acquisition is that it will bring together two vibrant open-source communities. “We look forward to continuing to support the Testcontainers open source project and look forward to what our teams do to expand it further,” he added.

Users of the open-source Testcontainers were reassured too, with Johnston saying that there are no plans to change the licensing structure of its components, and no plans to discontinue any of its projects.

Image: Docker