Senior Lead - AI Engineering

ZS is a place where passion changes lives. As a management consulting and technology firm focused on improving life and how we live it, we transform ideas into impact by bringing together data, science, technology and human ingenuity to deliver better outcomes for all. Here you’ll work side-by-side with a powerful collective of thinkers and experts shaping life-changing solutions for patients, caregivers and consumers, worldwide.

ZSers drive impact by bringing a client-first mentality to each and every engagement. We partner collaboratively with our clients to develop custom solutions and technology products that create value and deliver company results across critical areas of their business. Bring your curiosity for learning, bold ideas, courage and passion to drive life-changing impact to ZS.

We are seeking a highly motivated Applied AI Engineer
with a strong foundation in Machine Learning and a deep interest in Large Language Models (LLMs)and
Generative AI
. This role focuses on building, optimizing, and evaluating
production-grade LLM systems
, including
Retrieval-Augmented Generation (RAG), fine-tuning workflows, and scalable inference pipelines.

• Design and implement
  LLM-powered applications
  using state-of-the-art transformer models.
• Build and optimize
  RAG pipelines
  using embeddings, chunking strategies, and vector search.
• Experiment with
  prompt engineering
  ,
  structured outputs
  (JSON schemas/function calling), and
  tool-augmented LLMs
  (agents/workflows).
• Fine-tune models using techniques such as
  LoRA
  ,
  PEFT
  , and
  instruction tuning
  .
• Develop and evaluate
  embedding models
  for similarity search and semantic retrieval.
• Conduct
  LLM evaluation
  using automated and
  human-in-the-loop
  techniques (offline + online).
• Optimize inference workflows for
  latency
  , GPU utilization
  , and cost efficiency
  (quantization, batching, caching).
• Build and maintain REST API Services (FastAPI etc.)to deploy LLM/RAG endpoints, integrate with product systems, and support scalable inference.
• Contribute to integration of AI systems into
  production software environments
  (CI/CD, monitoring, reliability).
• Research and prototype cutting-edge approaches in Generative AI and share learnings with the team.

• A master's or bachelor's degree in Computer Science or related field from a top university
• 4+ years' hands-on experience in Machine Learning (ML) with production LLM systems
• Good fundamentals of machine learning, deep learning and fine tuning models (LLM) including:
  • Understanding of transformer architectures
  • Prompt engineering expertise
  • Embeddings and vector search
• Experienced in backend API design with FastAPI, async patterns, rate limiting
• Experience with vector DB including:
  • Pinecone, Weaviate, or Chroma
  • Embedding storage and similarity search
  • Hybrid search implementations
• Strong programming expertise in Python is must including:
  • Async programming (asyncio, async/await)
  • Type hints and Pydantic
  • SOLID principles and design patterns
• Experience in ML Ops to measure and track model performance including:
  • MLFlow for model tracking
  • Langfuse for LLM observability (strongly preferred)
  • Model versioning and A/B testing
• Experience in working with NLP & computer vision
• Fluency in English
• Client-first mentality
• Intense work ethic
• Collaborative spirit and problem-solving approach

• Cross-functional skills development & custom learning pathways
• Milestone training programs aligned to career progression opportunities
• Internal mobility paths that empower growth via s-curves, individual contribution and role expansions

At ZS, your growth matters. We offer a comprehensive total rewards package that supports your health and well‑being, financial future, time away, and professional development. With robust skills‑building programs, multiple career progression paths, internal mobility, and a deeply collaborative culture, you’ll have the opportunity to do meaningful work, expand your capabilities, and thrive as part of a global community. For details on total rewards in United States, visit ZS US office locations | Where…