Principal Machine Learning Engineer

Comcast • Philadelphia, PA

2d • Hybrid

About The Position

Comcast’s AI Search and Recommendation team is building the next generation of intelligent, personalized experiences across Comcast, Sky, and NBCUniversal. We’re looking for a Principal Machine Learning Engineer to lead the design and evolution of large-scale AI platforms powering search, ranking, and recommendations used by millions of customers. This is a high-impact, hands-on leadership role where you’ll shape technical strategy, build production-grade ML systems, and drive innovation in areas like personalization, generative AI, and real-time decisioning. You’ll work at the intersection of applied research and engineering, turning cutting-edge ideas into scalable products that directly influence customer experience and business outcomes.

Requirements

• 10+ years of experience in machine learning, AI, or software engineering
• Proven track record building and scaling production ML systems
• Strong Python programming skills with a focus on performance and reliability
• Experience translating advanced models or research into real-world products
• Background in search, ranking, recommendations, or personalization systems
• Familiarity with LLMs, generative AI, or agent-based systems
• Understand our Operating Principles; make them the guidelines for how you do your job.
• Own the customer experience think and act in ways that put our customers first, give them seamless digital options at every touchpoint, and make them promoters of our products and services.
• Know your stuff be enthusiastic learners, users and advocates of our game-changing technology, products and services, especially our digital tools and experiences.
• Win as a team make big things happen by working together and being open to new ideas.
• Be an active part of the Net Promoter System a way of working that brings more employee and customer feedback into the company by joining huddles, making call backs and helping us elevate opportunities to do better for our customers.
• Drive results and growth.
• Support a culture of inclusion in how you work and lead.
• Do what's right for each other, our customers, investors and our communities.

Responsibilities

• Lead AI Platform Strategy and Innovation: Own the architecture, roadmap, and evolution of core ML platforms supporting search, ranking, and recommendation systems. Define technical direction and deliver scalable solutions that enable personalization and relevance at massive scale.
• Drive High-Impact Programs: Lead complex, revenue-driving initiatives where machine learning is a key differentiator. Partner closely with Product, Engineering, and Data teams to align ML capabilities with business goals.
• Build Next-Generation AI Capabilities: Advance modern AI approaches including: Recommender systems and learning-to-rank models, Generative AI, LLM fine-tuning, and prompt engineering, Agentic AI systems integrating models with tools and workflows. Stay on the leading edge of AI and rapidly translate innovation into production systems.
• Architect and Scale ML Systems: Design and deploy distributed ML systems and real-time inference pipelines. Build end-to-end machine learning solutions—from data pipelines to model deployment, monitoring, and optimization.
• Stay Hands-On: Write and review production-quality code across core platforms and experimental projects. Lead technical design discussions and drive engineering excellence across teams.
• Influence Across the Organization: Mentor engineers and act as a technical leader across multiple teams. Establish best practices, reusable frameworks, and standards to scale innovation.

Benefits

• We believe that benefits should connect you to the support you need when it matters most, and should help you care for those who matter most. That's why we provide an array of options, expert guidance and always-on tools that are personalized to meet the needs of your reality—to help support you physically, financially and emotionally through the big milestones and in your everyday life. Please visit the benefits summary on our careers site for more details.

What This Job Offers

• Job Type: Full-time
• Career Level: Principal