The tech stack at ExpressVPN What our tech stack looks like

“What does your tech stack look like?”

If there’s one thing most engineering candidates ask about during job interviews, that’s it.

While a relatively straightforward question, it’s not exactly easy to answer. But our vice president of engineering, David, is probably the best-positioned person to explain the intricacies.

In his own words, David explains the various portions of our tech stack, along with how we utilize different platforms in our day-to-day operations.

The first world, IT Services, encompasses the apps that keep our business running. These are Google Docs, Github, Okta, and all the other SaaS products that tie together to make everybody productive. Integrating all of these pieces in a way that’s delightful for internal users is a big challenge, and we have a full-time engineering team that does a lot of slick engineering to make our various IT systems sing.

Read more: How our IT securely enables employee BYOD

The third world, client applications, includes our different VPN apps that everyone’s most familiar with. We build client applications for Windows, Mac, iOS, Android, Linux, and the browser extension. These applications are built in their native languages, like Java/Kotlin, Swift, C#, and JavaScript. There’s also a bit of C++ in some shared libraries.

The fifth world, the VPN itself, consists largely of TrustedServer, Lightway, and various services that manage all of those servers. Those services are often written in Ruby, Python, or C. We also leverage a lot of off-the-shelf components like Debian Linux, Ansible, and Rundeck. Many parts of this stack are “close to the metal,” so there’s a lot of focus on performance, memory management, and network throughout.

If you’re thinking, “That’s a lot!” Well, you’re right! We have dozens of dedicated engineers working to keep all these different pieces running together. We are actively hiring in all six of these “worlds,” so if anything here sounds interesting, we’d love to talk to you.