Antithesis provides deterministic, massively parallel simulation testing that validates complex distributed software systems before release.
ABOUT ANTITHESIS We provide a platform that enables engineering teams to identify and resolve bugs that traditional testing approaches miss. Antithesis runs your entire system in a deterministic simulation, breaks it in every way imaginable, and hands you a root cause and a perfect reproduction — no flaky tests, no false positives, no "works on my machine". This allows engineering teams to debug faster and ship with greater confidence. The rise of AI-generated code has made what we do more important than ever. Agents can write code faster than any human — but faster code isn't better code if it's buggy, stuck in review, or issues are slipping through the cracks undetected. The verification bottleneck is real and it's growing. This is exactly the problem Antithesis exists to solve. We've been quietly reinventing how the world thinks about software reliability, and we're just getting started. We're well-funded, deeply technical, and building a platform that tackles one of the most complex yet important problems in modern software engineering. If that sounds like fun to you, keep reading. ABOUT THE TEAM Engineers at Antithesis work across a wide range of domains, often developing their own tools along the way. They dig deep to understand how something really works -- but stay broad to ship features across the whole stack. The ideal Antithesis engineer is a generalist who loves to learn new things and will fearlessly hack on whatever is needed. The core requirements: you're smart, get things done, and a joy to work with. We're looking for Senior, Staff, and Principal Engineers to build the future of autonomous testing. No matter your particular field of experience, if you've been ambitiously building complex software and think you could be a fit; drop us a note. THE TECH Some of the tech and languages we use: - Nix. Lots of Nix. Nix for builds, Nix for infrastructure. Nix where you did not expect! - Rust for systems programming... and C/C++ where needed. - Typescript (and JS) on the front end. - All the other languages also: see our list of SDKs. https://antithesis.com/docs/using_antithesis/sdk/ THE PROJECTS We're looking for top-flight engineers to help us build: - A functional, reactive notebook https://antithesis.com/docs/multiverse_debugging/antithesis_notebook/ - A streaming, analytic database https://antithesis.com/blog/2025/testing_pangolin/ - (Semi-) formally proven https://www.youtube.com/watch?v=YQ78lX3glrY infrastructure - A custom, high-performance hypervisor https://antithesis.com/blog/deterministic_hypervisor/ - ...and other projects THE CULTURE Our team is comprised of people with a variety of backgrounds: standard engineering degrees to philosophy degrees; big-tech background to scrappy startups. But we have at least one common skill: everyone on the team, including managers, is held to the same high standard of engineering competency. In addition, we value in-person work for its value in building trust and sharing knowledge and mentoring each other. 5 days a week in-office job in Vienna, VA