Engineering Manager

About Antithesis

We've been quietly reinventing how the world thinks about software reliability, and we're just getting started! At Antithesis, we start at the foundations – we run entire software systems inside a deterministic simulation and break them in every way imaginable. Every issue then comes with a perfect reproduction, so you can identify root causes fast instead of spending days trying to recreate what went wrong.

The rise of AI-generated code has made this work more urgent than ever. Agents can write code faster than any human, but speed doesn't matter much when the output is buggy, stuck in review, or slipping through undetected. The verification bottleneck is real, it's growing, and solving it is one of the most consequential problems in software right now. That's what you'd be working on.

We're well-funded and deeply technical, the kind of place where the hardest problems get the most attention and the best ideas win regardless of who has them. If you want to do work that actually moves the needle on how reliable software can be, keep reading.

About This Role

We're opening our London office and we need someone to build it out right. As the Engineering Manager for Property-Based Testing in London, you'll be the founding leader of a team working on two products: Hegel , our property-based testing library family, and Bombadil , our open-source browser testing product. This isn't a "manage the roadmap and attend standups" kind of role — you'll be in the code, shaping architecture, and doing the hard technical work alongside your team.

You'll be the connective tissue between our London engineers and our Virginia-based core team, helping to establish the culture, norms, and technical standards that will define Antithesis in the UK. Building a new office from scratch is a rare opportunity. It's also a lot of work. We think that's exciting. Hopefully you do too.

What You'll Do

• Build the London team — hire exceptional engineers, onboard them well, and create the kind of environment where they do the best work of their careers.

• Foster Open Source Communities – Further our OSS testing frameworks by interacting with the community to build sustainable and rich relationships between Antithesis, our users, and the world.

• Get your hands dirty — write code, review code, debug gnarly issues, and set the technical bar by example.

• Drive delivery on complex, cross-functional projects — from early design through to production.

• Establish best practices that balance speed and correctness (we care a lot about correctness).

• Partner with Virginia to ensure London doesn't become an island — shared context, shared standards, shared wins.

• Mentor and develop your engineers, helping them grow both technically and professionally.

What We're Looking For

• Strong engineering chops — comfortable in C++, Python, Java, Go, or similar. You don't need to know every language we use, but you do need to be genuinely good at programming.

• Familiarity with property-based testing, fuzzing, or formal verification. You know what it means to prove software properties, not just test for them.

• Experience with test infrastructure, or developer tooling is a major plus (bonus points if you've shipped something open source).

• Proven track record of leading engineering teams — recruiting, mentoring, and growing talent, ideally in a startup or high-growth environment.

• Experience building or expanding a remote engineering office, distributed team, or cross-timezone function. (HQ is in the US)

• Strong technical judgment. You can make the right call on hard architectural questions and explain why clearly.

• Excellent communicator. You can align engineers, PMs, and executives around a shared direction without losing anyone along the way.

• Comfortable operating with ambiguity. We're early. Things change. You adapt.

About Our Team

Our team has backgrounds spanning traditional CS degrees, philosophy, mathematics, and everything in between — or nothing formal at all. What everyone shares is a high bar for engineering quality. Managers here are expected to meet that same bar: this isn't a role where you stop coding when you get the title. We also genuinely believe in in person work. It's how we build trust, share knowledge, and figure out hard problems together. That's why this role is 5 days a week in our London office.