Staff Software Engineer (AI Backend Services)

Pfizer; France; Hybride; EUR 90 000 - 130 000; Plein temps

Résumé du poste

Pfizer is seeking an AI Backend Python Engineer (Staff) to provide technical leadership for backend systems powering next-generation generative AI and LLM integrations. You will shape architecture on FastAPI, design scalable AWS-based platforms, and drive organizational engineering practices.

The role emphasizes mentorship, cross-functional collaboration with product and engineering leaders, and setting standards for observability, security, and performance across AI services.

Qualifications

• 7+ years of professional software engineering with backend and distributed systems experience.
• Proficient in Python for large-scale production systems.
• Deep knowledge of LLMs, generative AI architectures, and AI infrastructure (LangChain, litellm, Langfuse, OpenAI/Anthropic APIs).
• Proven track record architecting and delivering complex, scalable AWS-based platforms.

Responsabilités

• Define technical strategy and architecture for Python-based AI backend platforms (FastAPI) supporting LLM integration.
• Architect scalable, secure systems on AWS (Lambda, EKS) used by multiple teams.
• Drive engineering practices and platform capabilities across the org.
• Design AI observability using LangChain, Langfuse, and litellm; establish monitoring standards.

Connaissances

Python

FastAPI

AWS

LLMs

Microservices

Distributed systems

Mentoring

Code reviews

LangChain

Langfuse

Litellm

Docker

Kubernetes

Formation

Bachelor's/Master's in CS or related

Outils

Docker

Kubernetes

Terraform

Description du poste

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 solutionsBASIC 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 visionPREFERRED 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 organizationWork location assignment : Remote