Senior Principal AI Research Engineer

Pfizer • San Diego, CA

3d • $139,100 - $231,900 • Hybrid

About The Position

Pfizer is building an AI-native operating model for drug discovery, in which small, highly capable teams combine human expertise with AI to accelerate scientific and technical work. The Senior Principal AI Research Engineer will build machine learning systems that turn innovative models into secure, reliable, and scalable capabilities for scientists across Pfizer. The role has significant technical ownership and is described as intermediate-level.

The engineer will own an end-to-end subsystem, platform capability, or workflow; make architecture and design tradeoffs; deliver production-quality software and AI solutions; drive complex technical execution; influence engineering standards; and support less-experienced engineers through collaboration, reviews, and coaching. The work spans production AI systems, multimodal biomedical models, intelligent agents, data and retrieval pipelines, evaluation frameworks, knowledge systems, inference services, and human-in-the-loop workflows. The engineer will partner with AI scientists, computational biologists, data engineers, and platform teams to turn research prototypes into reusable, reliable, maintainable systems, and will improve their performance, reliability, usability, and scientific impact.

This is a hybrid role. Colleagues must live within commuting distance of a Pfizer location and work on-site an average of 2.5 days per week. The annual base salary range is $139,100 to $231,900, with eligibility for a Global Performance Plan bonus target of 17.5% of base salary and a share-based long-term incentive program. Pfizer offers benefits including retirement contributions, paid time off, leave, and health coverage. Relocation assistance may be available based on business needs and eligibility. Candidates must be authorized to work in the United States; U.S. work visa sponsorship is not available.

Requirements

• 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 and at least 2 years of relevant experience; OR a master's degree with at least 5 years of relevant experience; OR a bachelor's degree with at least 6 years of relevant experience.
• Demonstrated experience designing and delivering production software or machine learning systems.
• Experience owning technical solutions from architecture through deployment.
• Experience building reliable systems in cloud, distributed computing, or HPC environments.
• Experience developing maintainable, testable, and scalable software.
• Strong proficiency in Python software development.
• Strong proficiency with modern machine learning frameworks such as PyTorch or JAX.
• Strong proficiency in software architecture and system design.
• Strong proficiency in APIs, testing, debugging, version control, and technical documentation.
• Strong proficiency with containers, orchestration, CI/CD, and deployment workflows.
• Depth in one or more of the following: 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.
• Ability to work effectively across interdisciplinary teams, navigate ambiguity, solve complex problems, communicate technical concepts to broad audiences, influence decisions through expertise and execution, and support less-experienced teammates.
• Must be authorized to be employed in the United States by any employer; permanent U.S. work authorization is required and visa sponsorship is unavailable.

Nice To Haves

• 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.

Responsibilities

• 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 brings AI capabilities from experimentation into everyday scientific use.
• Translate scientific and business needs into technical solutions.
• Lead architecture, implementation, testing, deployment, monitoring, and continuous improvement for an area of ownership.
• Drive projects from concept through production and operational support.
• Partner with AI scientists, computational biologists, data engineers, and platform teams.
• Transform prototypes into reusable, reliable, and maintainable systems with clear interfaces, measurable performance, and long-term sustainability.
• Balance performance, scalability, cost, reliability, security, privacy, maintainability, and delivery speed in engineering decisions.
• Strengthen model evaluation, observability, reproducibility, lineage, security, and operational resilience to support responsible AI deployment.
• Contribute to architecture reviews, code reviews, engineering standards, and reusable technical patterns.
• Troubleshoot complex problems and improve engineering quality across the organization.
• Guide and support less-experienced engineers through collaboration and mentorship.
• Define success metrics and operational indicators, and continuously improve performance, reliability, usability, and scientific impact.

Benefits

• 401(k) plan with Pfizer matching contributions and an additional Pfizer Retirement Savings Contribution.
• Paid vacation, holidays, and personal days.
• Paid caregiver/parental and medical leave.
• Medical, prescription drug, dental, and vision coverage.
• Eligibility to participate in Pfizer’s Global Performance Plan, with a bonus target of 17.5% of base salary.
• Eligibility to participate in a share-based long-term incentive program.
• Relocation assistance may be available based on business needs and/or eligibility.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: Ph.D. or professional degree