Senior Principal AI Research Engineer

Help Build a New AI-Native Operating Model At Pfizer, we're investing in the future of AI-enabled drug discovery. This role is about more than using AI to improve existing ways of working. We are building a new operating model in which small, highly capable teams combine human expertise with AI to achieve outcomes and move at a pace that previously required much larger organizations. We are looking for people who want to help invent and champion that model: individuals willing to rethink how work is organized, how problems are decomposed, what can be delegated to intelligent systems, and how humans and AI work together most effectively. Successful candidates will use AI not simply as a productivity tool, but as a means to fundamentally transform how scientific and technical work gets done—and will help others across R&D adopt these new ways of working. Why This Role Is Different Own Meaningful Problems You'll own critical AI capabilities from architecture through production deployment. Rather than contributing to isolated components, you'll lead the design and delivery of end-to-end systems that directly enable scientific discovery. Work Where AI Meets Real-World Impact The systems you build will support researchers tackling some of the toughest challenges in medicine, helping accelerate insights across discovery, development, and translational science. Operate at the Frontier of AI You will work across technologies and domains including:

• Large Language Models (LLMs)
• Agentic AI Systems
• Multimodal Learning
• Scientific Machine Learning
• Retrieval-Augmented Generation (RAG)
• Knowledge Graphs
• Distributed Training and Inference
• AI Platforms and MLOps
• AI Evaluation and Benchmarking

Accelerate Your Growth You'll work alongside experts in AI, engineering, computational biology, and drug discovery while taking on increasing technical ownership and influence. Build, Ship, Learn, Repeat We value engineers who can move from ambiguity to execution, convert ideas into working systems, measure outcomes, and continuously improve based on real-world feedback. The Opportunity As a Senior Principal AI Research Engineer, you will build the machine learning systems that transform innovative models into secure, reliable, and scalable capabilities for scientists across Pfizer. This is an intermediate-level engineering role with significant technical ownership. You will:

• Own an end-to-end subsystem, platform capability, or workflow
• Make sound architecture and design tradeoff decisions
• Deliver production-quality software and AI solutions
• Drive technical execution for complex projects
• Influence engineering standards and best practices
• Help less-experienced engineers grow through collaboration, code reviews, and technical coaching

Success in this role requires strong engineering fundamentals, demonstrated experience delivering production systems, and the ability to operate effectively in an environment where science, technology, and business impact intersect. What You'll Do Build the AI Systems Behind Tomorrow's Scientific Breakthroughs

• Design, develop, and deploy production-grade AI systems supporting multimodal biomedical models and intelligent agents
• Engineer data pipelines, retrieval systems, evaluation frameworks, knowledge systems, inference services, and human-in-the-loop workflows
• Create scalable software that enables AI capabilities to move beyond experimentation and into everyday scientific use

Own End-to-End Technical Delivery

• Translate scientific and business needs into technical solutions
• Lead architecture, implementation, testing, deployment, monitoring, and continuous improvement for your area of ownership
• Drive projects from concept through production and operational support

Turn Research Into Impact

• Partner closely with AI scientists, computational biologists, data engineers, and platform teams
• Transform promising prototypes into reusable, reliable, and maintainable systems
• Develop solutions with clear interfaces, measurable performance, and long-term sustainability

Make Thoughtful Engineering Tradeoffs

• Balance performance, scalability, cost, reliability, security, privacy, maintainability, and speed of delivery
• Apply sound engineering judgment when evaluating technical approaches and system architecture decisions

Build Trusted and Responsible AI

• Strengthen model evaluation, observability, reproducibility, lineage, security, and operational resilience
• Implement practices that support responsible and trustworthy AI deployment within scientific environments

Raise the Engineering Bar

• Contribute to architecture reviews, code reviews, engineering standards, and reusable technical patterns
• Troubleshoot complex problems and improve engineering quality across the organization
• Provide guidance and support to less-experienced engineers through collaboration and mentorship

Deliver Measurable Outcomes

• Define success metrics and operational indicators
• Continuously improve performance, reliability, usability, and scientific impact
• Help teams adopt AI with confidence and scale

What Makes You a Strong Fit Education & Experience

• PhD in Computer Science, Computer Engineering, Electrical Engineering, Applied Mathematics, or a related technical discipline with demonstrated experience building software, systems, or machine learning solutions with 2+ years of relevant experience; OR
• Master's degree with 5+ years of relevant experience; OR
• Bachelor's degree with 6+ years of relevant experience

Technical Expertise You have demonstrated experience:

• Designing and delivering production software or machine learning systems
• Owning technical solutions from architecture through deployment
• Building reliable systems in cloud, distributed computing, or HPC environments
• Developing maintainable, testable, and scalable software

Engineering Proficiency You bring strong proficiency in:

• Python software development
• Modern machine learning frameworks such as PyTorch or JAX
• Software architecture and system design
• APIs, testing, debugging, version control, and technical documentation
• Containers, orchestration, CI/CD, and deployment workflows

You have depth in one or more of the following areas:

• Distributed GPU training
• Model serving and inference optimization
• AI platforms and MLOps
• Data and knowledge systems
• LLM and agentic architectures
• Retrieval systems and RAG
• AI evaluation frameworks
• Performance and infrastructure optimization

Collaboration & Leadership You have a proven ability to:

• Work effectively across interdisciplinary teams
• Navigate ambiguity and solve complex problems
• Communicate technical concepts to broad audiences
• Influence decisions through expertise and execution
• Support and develop less-experienced teammates

Preferred Qualifications

• Experience in life sciences, healthcare, biotechnology, or highly regulated industries
• Experience with multimodal AI, scientific machine learning, computational biology, or cheminformatics
• Experience implementing responsible AI practices, evaluation frameworks, and governance controls
• Evidence of technical impact through deployed systems, publications, patents, open-source contributions, or reusable engineering platforms

How You'll Succeed The most successful engineers in this role:

• Take ownership and consistently deliver
• Balance innovation with engineering discipline
• Embrace difficult technical challenges
• Learn quickly and continuously
• Build trust through execution and collaboration
• Help elevate the capabilities of the broader team
• Stay focused on outcomes and scientific impact

Why Pfizer AI is becoming a foundational capability across Pfizer's R&D organization. We are building an environment where exceptional engineers can tackle technically ambitious challenges, work with world-class scientific experts, and contribute to innovations that have the potential to improve lives around the world. Here, you'll find:

• Meaningful ownership
• Complex technical challenges
• Exceptional collaborators
• Significant opportunities for growth
• The ability to build AI with real-world impact

If you want to build production AI at scale while helping shape the future of scientific discovery, this is an opportunity to do the most meaningful work of your career. Work Location Assignment This is a hybrid role requiring colleagues to live within commuting distance of a Pfizer location and work on-site an average of 2.5 days per week. The annual base salary for this position ranges from $139,100.00 to $231,900.00. In addition, this position is eligible for participation in Pfizer’s Global Performance Plan with a bonus target of 17.5% of the base salary and eligibility to participate in our share based long term incentive program. We offer comprehensive and generous benefits and programs to help our colleagues lead healthy lives and to support each of life’s moments. Benefits offered include a 401(k) plan with Pfizer Matching Contributions and an additional Pfizer Retirement Savings Contribution, paid vacation, holiday and personal days, paid caregiver/parental and medical leave, and health benefits to include medical, prescription drug, dental and vision coverage. Learn more at Pfizer Candidate Site – U.S. Benefits | (uscandidates.mypfizerbenefits.com). Pfizer compensation structures and benefit packages are aligned based on the location of hire. The United States salary range provided does not apply to Tampa, FL or any location outside of the United States. This role is posted in multiple locations. If you are applying for the role in an secondary job posting location where pay transparency regulations apply, your Talent Advisor will share the local pay information with you during the first interview. Relocation assistance may be available based on business needs and/or eligibility. Candidates must be authorized to be employed in the U.S. by any employer. U.S. work visa sponsorship (such as TN, O-1, H-1B, etc.) is not available for this role now or in the future. Sunshine Act Pfizer reports payments and other transfers of value to health care providers as required by federal and state transparency laws and implementing regulations. These laws and regulations require Pfizer to provide government agencies with information such as a health care provider’s name, address and the type of payments or other value received, generally for public disclosure. Subject to further legal review and statutory or regulatory clarification, which Pfizer intends to pursue, reimbursement of recruiting expenses for licensed physicians may constitute a reportable transfer of value under the federal transparency law commonly known as the Sunshine Act. Therefore, if you are a licensed physician who incurs recruiting expenses as a result of interviewing with Pfizer that we pay or reimburse, your name, address and the amount of payments made currently will be reported to the government. If you have questions regarding this matter, please do not hesitate to contact your Talent Acquisition representative. EEO & Employment Eligibility Pfizer is committed to equal opportunity in the terms and conditions of employment for all employees and job applicants without regard to race, color, religion, sex, sexual orientation, age, gender identity or gender expression, national origin, disability or veteran status. Pfizer also complies with all applicable national, state and local laws governing nondiscrimination in employment as well as work authorization and employment eligibility verification requirements of the Immigration and Nationality Act and IRCA. Pfizer is an E-Verify employer. This position requires permanent work authorization in the United States. Pfizer endeavors to make accessible to all users. If you would like to contact us regarding the accessibility of our website or need assistance completing the application process and/or interviewing, please email View email address on joinrs.com. This is to be used solely for accommodation requests with respect to the accessibility of our website, online application process and/or interviewing. Requests for any other reason will not be returned. To learn more about acceptable and prohibited uses of AI during the recruitment process, please review our candidate AI-use guidelines available on Pfizer Careers. Information & Business Tech