Senior Machine Learning Engineer

Cybersecurity titans are born when a new attack vector overwhelms existing defenses. When ransomware ran rampant, CrowdStrike emerged as the category leader for securing user endpoints. Today, AI has made account compromise the #1 cybercrime . LLM-powered phishing messages get past email security, allowing attackers to compromise accounts and exfiltrate sensitive data in minutes. Incumbents can't keep up. They catch these attacks late, or miss them altogether.

Enter Petra, security for when no perimeter remains. We are building an AI-driven Detection and Response platform to catch and remove attackers before they can act.

We've grown very quickly, reaching mid-7-figures in ARR in under a year — we now protect over 2.5 million users across 10,000+ businesses. We price premium, yet have extremely low customer churn. Our customers consistently tell us that Petra is the best product they've ever used . You can see a demo here .

Ownership is everything here. You'll be responsible for our core ML detection platform, and the systems you build are what separate Petra from every other player in this space.

Petra is a premium product and it's everyone's job to make sure it stays that way. That means you won't just train models — you'll talk to customers, understand the attacks they're facing, and think creatively about how to find the next signal that widens the gap between us and second place.

Concretely, you will:

Build and evolve our detection models. Working closely with our CTO and Head of Machine Learning, you'll design and build the ML systems that identify account compromise in real time.

Take models from research to production. You don't just care about model performance in a notebook. You're energized by measuring how your models behave at scale in a live system with real attackers.

Architect for scale. We're growing fast. Nothing excites you more than architecting and implementing an elegant solution that'll handle 10-100x the scale in 6 months.