Zealot (zealotlabs.com) builds AI systems that find zero-days, emulate target devices, and develop working exploits for U.S. defense and intelligence customers. We are backed by tier-1 U.S. venture firms and industry leaders, with a team that includes alumni of Anthropic, xAI, NSA, USCYBERCOM and Anduril.
The opportunity
We are looking for an exceptional generalist engineer who can turn rough, high-stakes ideas into working systems. You will operate across product, backend, infrastructure, AI systems, and whatever else the problem requires—from first principles through deployment and iteration.
This is a high-agency role on a small, deeply technical team. You will work closely with founders, researchers, security specialists, and customers, with real influence over what we build and how we build it.
What you’ll do
- Own ambiguous projects end to end. Start with an incomplete idea, identify the underlying objective, choose the right scope, and ship a useful result.
- Build wherever the problem lives. Move across product surfaces, APIs, data pipelines, infrastructure, internal tooling, and systems code as needed.
- Make sharp tradeoffs. Decide when the right answer is a fast prototype, a durable system, or something in between—and explain why.
- Stay close to the details. Debug through the stack, understand failure modes, and improve the system rather than treating abstractions as black boxes.
- Anticipate what comes next. Spot bottlenecks, risks, and opportunities before they become assigned work.
- Communicate with precision. Make decisions legible through concise written updates, clear technical reasoning, and direct conversations.
What we look for
- Exceptional engineering ability, demonstrated through production systems, technically ambitious side projects, open-source work, or other concrete evidence.
- High agency and urgency: you do not wait for perfect instructions, and you follow through without needing heavy process.
- Ruthless prioritization: you can separate what matters now from what can wait, and resist premature complexity.
- Sound technical judgment: you understand how to build something “right” at scale, while knowing when that is the wrong choice for the current stage.
- Technical depth: you are comfortable getting below framework-level abstractions and reasoning about how the code and system actually work.
- Conviction without ego: you form clear opinions from experience, defend them thoughtfully, and update them when the evidence changes.
- Clear, concise communication and a low-drama, high-trust working style.
- Curiosity and a steep trajectory: you learn quickly, explore beyond your assigned scope, and keep raising your own ceiling.
Experience that tends to translate well
There is no single ideal path. Strong candidates may have built at an early-stage startup, moved between a startup and a large technology company, or repeatedly created substantial projects outside work. We especially value people who have seen what scale requires, but do not import scale-company process before it is useful.
- Meaningful ownership in a pre-seed through Series B company, founding team, or similarly resource-constrained environment.
- Full-stack product engineering combined with depth in backend, infrastructure, distributed systems, developer tooling, low-level systems, security, or AI systems.
- A record of shipping projects from a blank page and operating them after launch.
- Side projects that reveal taste, technical ambition, curiosity, or a desire to build before anyone asks.
How we work
We move quickly, debate ideas directly, and care more about outcomes than titles or territory. This is an intense, founder-close environment, and occasional deadline-driven pushes are part of the job. We want teammates who lean in when the mission demands it, enjoy spending real time with the people they work with, and help make that intensity purposeful, shared, and sustainable.
Why join
- Mission with consequence. Build capabilities that matter to national security customers.
- Unusually broad ownership. Shape systems, priorities, and engineering standards while the company is still small.
- A technically demanding team. Work alongside people from frontier AI, offensive security, defense, and high-performance engineering environments.
- A steep growth curve. Take on problems whose scope would be split across multiple teams at a larger company.