Principal Machine Learning Engineer: Zscaler (Cybersecurity / Zero Trust)

This is not a generic ML role; it is a specialized Adversarial AI position. Zscaler processes billions of transactions. They are looking for a high-level Individual Contributor (IC) to build "Agentic Frameworks"—AI systems that don't just detect threats but autonomously reason through them.The "Principal" aspect implies:Architecture over Code: While you will code, your primary value is designing the systems that junior engineers build.Ambiguity Tolerance: You are expected to define the technical roadmap for "Agentic AI" in cybersecurity, rather than just executing tickets.## Key Technical Themes & RequirementsThe JD highlights three distinct technical pillars you must possess:1. Advanced AI & AgentsThey explicitly mention "Agentic frameworks" and "Multi-agent systems."What they want: Experience building LLM-based agents that can use tools (function calling) to investigate security alerts.Keywords to know: ReAct patterns, Orchestration (LangChain/LangGraph), AutoGen, CrewAI.2. Mathematical Rigor (Adversarial ML)Unlike standard commercial ML, this role asks for "Game Theory," "Optimization," and "Verification."Why? Cybersecurity is a zero-sum game. You are building models to defeat an intelligent adversary who is actively trying to trick your model.The Math: You should be comfortable discussing minimax problems ($\min_{\theta} \max_{\delta} L(f_\theta(x + \delta), y)$) and formal verification methods to prove a model cannot be bypassed.3. Scale & InfrastructureZscaler operates 160+ data centers.The Constraint: Your models cannot introduce latency. Anomaly detection must happen in milliseconds.The Stack: Deep familiarity with AWS/GCP and pipelines that handle massive throughput is non-negotiable.## Compensation AnalysisThe listed range is $182k - $260k Base Salary.Context: For a "Principal" title in San Jose, this base is standard, but the Total Compensation (TC) will be significantly higher due to RSUs (Restricted Stock Units) and bonuses.Estimation: At a public company like Zscaler, a Principal Engineer's equity package can range from $150k to $300k+ per year on top of base salary.Negotiation: Focus your negotiation on the Equity component, as that is where the leverage exists for this level of seniority.## Application StrategyIf you apply, your resume and cover letter must explicitly bridge the gap between Machine Learning and Cybersecurity.Do not submit a generic Data Science resume.Do highlight the following:Specific Security Outcomes: "Built an anomaly detection model that reduced false positives by 40%."Agentic Experience: "Designed a multi-agent system capable of automated root-cause analysis for system outages."Production Scale: "Deployed models serving 1M+ QPS (Queries Per Second)."