AI Backend Python Engineer (Staff)

The AI Backend Python Engineer (Staff) will provide technical leadership and define the architecture for Back End systems that power the next generation of generative AI applications and large language model (LLM) integrations. This role focuses on driving strategic technical direction, designing platform-level solutions using Python, FastAPI, and AWS, and influencing engineering practices across the organization., * Define technical strategy and architecture for Python-based AI Back End platforms (on FastAPI) that support LLM integration, generative AI pipelines, and AI agent orchestration

• Architect scalable, reliable, and secure systems on AWS infrastructure (Lambda, EKS) that serve as the foundation for multiple teams
• Drive technical decisions that impact organization-wide engineering practices and platform capabilities
• Design and champion AI system observability using LangChain, Langfuse, and litellm
• Establish engineering standards for monitoring, logging, observability, and operational excellence across AI Back End services
• Lead cross-functional initiatives to optimize performance, security, and scalability of large-scale AI applications
• Mentor and technically guide engineers at all levels, elevating team capabilities through code reviews, architecture reviews, and technical leadership
• Identify technical debt, performance bottlenecks, and architectural limitations; drive long-term solutions
• Collaborate with engineering leadership, product, and other stakeholders to align technical strategy with business objectives
• Influence technology choices, design patterns, and best practices across the AI Software & Operations department
• Represent the team in organization-wide technical discussions and drive adoption of innovative solutions

• 7+ years of professional software engineering experience with extensive Back End and distributed systems expertise
• Deep expert-level proficiency in Python for building large-scale production systems
• Comprehensive understanding of LLMs, generative AI architectures, and AI infrastructure (LangChain, litellm, Langfuse, OpenAI/Anthropic APIs)
• Proven track record of architecting and delivering complex, scalable platforms on AWS
• Expert knowledge of microservices architecture, distributed systems design, and event-driven architectures
• Demonstrated experience with containerization, orchestration (Docker/Kubernetes), and cloud-native patterns
• Strong history of technical leadership, mentoring engineers, and driving organizational impact
• Bachelor’s or Master’s degree in Computer Science, Engineering, or related field, or equivalent practical experience

• Excellent strategic thinking and ability to balance short-term delivery with long-term architectural vision *, * Extensive experience designing and building platform-level infrastructure for AI/ML workloads at scale

• Deep expertise in FastAPI, asynchronous Python, and high-performance Back End systems
• Proven track record of architecting event-driven and Real Time systems for AI applications
• Experience influencing engineering culture, establishing best practices, and driving technical standards
• Strong background in MLOps, model deployment strategies, and AI system reliability
• Expertise with infrastructure-as-code, CI/CD automation, and platform engineering
• Experience working with product and business stakeholders to translate requirements into technical strategy
• History of leading cross-functional technical initiatives with measurable organizational impact
• Published technical work, open-source contributions, or recognized expertise in AI Back End systems
• Exceptional communication and influence skills across all levels of the organization

Pfizer is an equal opportunity employer and complies with all applicable equal employment opportunity legislation in each jurisdiction in which it operates.