Senior Backend Engineer

Job description

About Antithesis We make software that finds the bugs your engineers couldn't. 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." We've been quietly reinventing how the world thinks about software reliability, and we're just getting started. 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 slipping through the cracks undetected. The verification bottleneck is real, it's growing, and it's exactly the problem we exist to solve. We're well-funded, deeply technical, and building something genuinely hard. If that sounds like fun to you, keep reading. About the Role: The Platform team is the engine room of Antithesis — we own the infrastructure, services, and tools that are at the core of the product. As a Senior Backend Engineer here, you won't be maintaining someone else's abstractions. You'll be designing them from scratch, owning them end-to-end, across the full stack: from raw b...