Staff Software Engineer (AI Backend Services)

ROLE DESCRIPTION The AI Backend Python Engineer (Staff) will provide technical leadership and define the architecture for backend 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. KEY RESPONSIBILITIES Define technical strategy and architecture for Python-based AI backend 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 backend 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 BASIC QUALIFICATIONS 7+ years of professional software engineering experience with extensive backend 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 PREFERRED QUALIFICATIONS Extensive experience designing and building platform-level infrastructure for AI/ML workloads at scale Deep expertise in FastAPI, asynchronous Python, and high-performance backend 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 backend systems Exceptional communication and influence skills across all levels of the organization Work location assignment : Remote 
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.

 Pfizer is an equal opportunity employer and complies with all applicable equal employment opportunity legislation in each jurisdiction in which it operates. Égalité des chances & Emploi Nous croyons que des équipes diversifiées et inclusives sont essentielles à la réussite d'une entreprise. En tant qu'employeur, Pfizer s'engage à valoriser la diversité et l’inclusion sous toutes ses formes. Cette diversité se reflète également à travers les patients et les communautés que nous servons. Ensemble, continuons à bâtir une culture qui encourage, soutient et responsabilise nos employés. Handicap & Inclusion Notre mission est de libérer le potentiel de nos collaborateurs et nous sommes fiers d'être un employeur inclusif pour les personnes handicapées, garantissant ainsi l'égalité des chances en matière d'emploi pour tous les candidats. Nous vous encourageons à donner le meilleur de vous-même en sachant que nous apporterons tous les ajustements raisonnables pour soutenir votre candidature et votre carrière future. Votre expérience avec Pfizer commence ici ! 
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