Principal Machine Learning Engineer

Cisco•San Jose, CA

2d•$291,500 - $424,400

About The Position

We are an agile team with a startup feel and a strong bias for action. We move fast, embrace failure as part of the process, and stay focused on solving real-world problems for defenders on the front lines. Our team blends deep expertise in AI, cybersecurity, and platform engineering. We are driven by a shared belief that the only way to outpace hackers is through AI advancements that free up humans to tackle real threats and more challenging problems. This is a place for builders who thrive in ambiguity, challenge the status quo, and care deeply about making a meaningful impact. If you're energized by tough problems, excited to shape the future of cyber defense, and eager to work alongside passionate experts, you'll feel right at home.

Requirements

Bachelor's degree with 12+ years of related experience, Master's degree with 7+ years of related experience, or PhD with 5+ years of related experience.
Experience designing and building scalable backend services, APIs, and automation solutions using Python.
Experience with Security Operations concepts, including threat detection, triage, investigation, and incident response.
Experience designing, developing, and integrating AI-powered solutions using Large Language Models (LLMs), including prompt engineering, agentic AI workflows, and AI application development.
Experience working with security telemetry (e.g., endpoint, network, authentication, cloud, or similar data sources) and building automation or detection workflows that leverage security data.

Nice To Haves

Experience building and integrating product APIs to automate Security Operations workflows.
Experience evaluating AI model performance using structured experimentation, including accuracy, reliability, usability, latency, and cost optimization.
Experience designing evaluation frameworks and experiments for LLM-based applications.
Experience with SIEM and SOAR platforms, such as Splunk, from a practitioner, engineering, or automation perspective.
Experience as a Tier 3 SOC Analyst, Detection Engineer, Security Automation Engineer, or similar Security Operations role.
Experience developing Retrieval-Augmented Generation (RAG) applications and working with vector databases such as Pinecone, FAISS, or similar technologies.
Experience with LLM fine-tuning, embedding models, or domain-specific AI customization for cybersecurity applications.
Experience building scalable security data pipelines for ingesting, parsing, enriching, and normalizing high-volume security telemetry.
Passion for designing intuitive AI-assisted analyst experiences with a focus on usability, explainability, trust, and human-centered design.
Experience collaborating across Product Management, Engineering, and Security Research to rapidly deliver customer-focused AI capabilities.

Responsibilities

Design and build agentic workflows that combine detection signals, context, and playbooks to automate threat triage and response.
Prototype and test new AI features—from enrichment agents to incident summarization—working closely with Security SMEs to validate real-world utility.
Develop an AIOps pipeline to enable rapid experimentation with prompts, models, and RAG systems, using clear, measurable success criteria to evaluate iterations.
Evaluate model outputs for accuracy, reliability, and usability, then prototype and deploy improvements based on structured feedback and testing.
Collaborate with Product and Platform teams to co-design AI-enhanced TDIR workflows that are intuitive, scalable, and immediately useful to analysts.
Contribute to the core architecture powering AI-native security operations, helping shape how Splunk and Cisco scale trusted automation across the enterprise.

Benefits

medical, dental and vision insurance
a 401(k) plan with a Cisco matching contribution
paid parental leave
short and long-term disability coverage
basic life insurance
10 paid holidays per full calendar year
1 floating holiday for non-exempt employees
1 paid day off for employee’s birthday
paid year-end holiday shutdown
4 paid days off for personal wellness
16 days of paid vacation time per full calendar year (non-exempt employees)
flexible vacation time off program (exempt employees)
80 hours of sick time off provided on hire date and each January 1st thereafter
up to 80 hours of unused sick time carried forward from one calendar year to the next
Optional 10 paid days per full calendar year to volunteer