Principal Machine Learning Engineer

Make your mark at Comcast -- a Fortune 30 global media and technology company. From the connectivity and platforms we provide, to the content and experiences we create, we reach hundreds of millions of customers, viewers, and guests worldwide. Become part of our award-winning technology team that turns big ideas into cutting-edge products, platforms, and solutions that our customers love. We create space to innovate, and we recognize, reward, and invest in your ideas, while ensuring you can proudly bring your authentic self to the workplace. Join us. You'll do the best work of your career right here at Comcast. (In most cases, Comcast prefers to have employees on-site collaborating unless the team has been designated as virtual due to the nature of their work. If a position is listed with both office locations and virtual offerings, Comcast may be willing to consider candidates who live greater than 100 miles from the office for the remote option.)
Job Summary
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.
Job Description
Responsibilities/what you'll do:
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

Qualifications:

• 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

Employees at all levels are expected to:

• 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.

Disclaimer: This information has been designed to indicate the general nature and level of work performed by employees in this role. It is not designed to contain or be interpreted as a comprehensive inventory of all duties, responsibilities and qualifications.
Comcast is an equal opportunity workplace. We will consider all qualified applicants for employment without regard to race, color, religion, age, sex, sexual orientation, gender identity, national origin, disability, veteran status, genetic information, or any other basis protected by applicable law.
Skills:
Machine Learning (ML); Business Acumen; Technical Leadership; Learning Agility; Design; Communication
Base pay is one part of the Total Rewards that Comcast provides to compensate and recognize employees for their work. Most sales positions are eligible for a Commission under the terms of an applicable plan, while most non-sales positions are eligible for a Bonus. Additionally, Comcast provides best-in-class Benefits to eligible employees. 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 compensation and benefits summary on our careers site for more details.
Education
Bachelor's Degree
While possessing the stated degree is preferred, Comcast also may consider applicants who hold some combination of coursework and experience, or who have extensive related professional experience.
Relevant Work Experience
10 Years +