Senior Machine Learning Engineer

A fast-growing, YC-backed cybersecurity startup protecting small and mid-sized businesses from account takeover, hiring a senior ML engineer to own its core detection platform.


This is a senior machine learning engineer role with real ownership of the detection models that set the product apart from its competitors. You'll work with the CTO and Head of Machine Learning to build systems that spot account compromise in real time, then watch how they perform against live attackers. The team is lean and the company is growing quickly, so your opinions will shape how things get built.

Role: Senior Machine Learning Engineer
Salary: $250,000 to $400,000 plus competitive equity
Location: San Francisco, on-site 5 days a week

What you'll be doing:

• Own the core ML detection platform that sets the product apart in the market
• Design and build the models that identify account compromise in real time
• Work closely with the CTO and Head of Machine Learning on detection strategy
• Take models from research into production and measure how they behave at scale against real attackers
• Talk to customers to understand the attacks they face, and look for the next signal that widens the gap on competitors
• Design systems that can handle 10 to 100 times the current scale
• Set patterns and push for correctness as a senior voice on a small team
• Raise the quality of the engineering around you
• Work across a stack of Node, TypeScript, React and Python

What you'll need:

• 4+ years machine learning engineering experience, with meaningful time shipping models into production at scale
• Strong quantitative fundamentals: probability and statistics, linear algebra, anomaly detection, behavioural modelling and NLP
• Experience training and deploying models in production, and a clear view of the limitations of each approach
• Strong engineering fundamentals, with clean, production-grade Python and the confidence to own a system end to end
• Experience with real-time or streaming data pipelines, feature stores, high-performance databases and distributed systems
• High agency: you spot the problem, propose the fix and ship it
• The ability to move quickly and find the 90/10 rather than chasing perfect
• Comfort in a small, high-autonomy team where scope is rarely handed to you
• US work authorisation, as visa sponsorship is not available

Nice to have:

• Experience in high-stakes domains such as quantitative finance or fraud detection
• A background in cybersecurity or threat detection
• Experience with Node and TypeScript alongside Python

This role would suit a senior ML engineer who wants to own a detection platform end to end, enjoys working close to customers and real attackers, and would rather shape a lean team than join a large one with a fixed playbook.