Senior Lead AI Engineer - LLM & RAG Systems

ZS; Bellevue (WA); Hybrid; USD 180,000 - 260,000; Full time

Benefits offered by this job

Hybrid work model

Travel opportunities

Total rewards package

Job summary

ZS is seeking an Applied AI Engineer to design, build, and optimize production-grade LLM systems and RAG pipelines. You will work on prompt engineering, embeddings, and tool-augmented LLMs, delivering scalable AI capabilities within a consulting-teams environment.

Responsibilities include developing RESTful services with FastAPI, evaluating models, and improving latency, cost, and reliability. Hybrid work and travel are common in this role.

Qualifications

• 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.
• Strong fundamentals of ML/DL and fine tuning models (LLM) including transformers, prompt engineering, embeddings and vector search.
• Experience in backend API design with FastAPI, async patterns, rate limiting.

Responsibilities

• 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 LoRA/PEFT/instruction tuning.
• Develop and evaluate embedding models for similarity search and semantic retrieval.
• Conduct LLM evaluation with automated and human-in-the-loop methods (offline + online).
• Optimize inference workflows for latency, GPU utilization, and cost (quantization, batching, caching).
• Build and maintain REST API Services (FastAPI etc.) to deploy LLM/RAG endpoints and support scalable inference.
• Integrate AI systems into production software environments (CI/CD, monitoring, reliability).
• Research and prototype cutting-edge approaches in Generative AI and share learnings.

Skills

Prompt engineering

Vector search

Python programming

Async programming

FastAPI

ML Ops

NLP/Computer Vision

English fluency

Education

Bachelor's or Master's in CS or related

Tools

Pinecone/Weaviate/Chroma

Langfuse

MLFlow

LLM frameworks

REST APIs

Job description

ZS is seeking an Applied AI Engineer to design, build, and optimize production-grade LLM systems and RAG pipelines. You will work on prompt engineering, embeddings, and tool-augmented LLMs, delivering scalable AI capabilities within a consulting-teams environment.

Responsibilities include developing RESTful services with FastAPI, evaluating models, and improving latency, cost, and reliability. Hybrid work and travel are common in this role.