Staff Machine Learning Engineer

PayPal • San Jose, CA

2d • $196,500 - $291,500 • Hybrid

About The Position

As a Staff Engineer, you will lead the design, development, and implementation of advanced machine learning (ML), large language model (LLM), and agentic AI systems that solve complex business and customer problems. You will translate emerging AI capabilities into scalable, reliable solutions that improve products, strengthen internal operations, and create measurable business value. The role combines hands-on engineering, architectural leadership, and close collaboration with data scientists, software engineers, product managers, and business stakeholders.

Requirements

• At least 5 years of relevant experience and a bachelor's degree, or an equivalent combination of education and experience.
• Extensive experience with ML frameworks such as TensorFlow, PyTorch, or scikit-learn.
• Expertise in cloud platforms (AWS, Azure, or GCP) and tools for data processing and model deployment.

Nice To Haves

• Master’s or PhD in Computer Science, Machine Learning, or a related field.
• Proven experience designing and developing deep neural network (DNN) solutions.
• Experience building large-scale advertising, recommendation, search, and ranking systems, and user modeling, including personalization, embeddings, retrieval, learning-to-rank, and user behavior and intent modeling.
• Hands-on experience building and shipping production LLM applications, including fine-tuning (e.g., LoRA/PEFT), retrieval-augmented generation (RAG), and prompt engineering.
• Experience designing agentic systems with tool use, planning, memory, and multi-agent orchestration using frameworks such as LangGraph, LangChain, AutoGen, or Model Context Protocol (MCP).
• Experience with LLM and agent evaluation, guardrails, and observability, including offline/online evaluations and hallucination detection.
• Experience optimizing LLM inference for latency and cost, such as with vLLM, quantization, distillation, or GPU serving.

Responsibilities

• Lead the development and optimization of advanced machine learning models.
• Oversee the preprocessing and analysis of large datasets.
• Deploy and maintain ML solutions in production environments.
• Collaborate with cross-functional teams to integrate ML models into products and services.
• Monitor and evaluate deployed model performance, making necessary adjustments.
• Lead the design, development, and implementation of advanced ML, LLM, and agentic AI systems.

Benefits

• Generous paid time off.
• Healthcare coverage for employees and their families.
• Resources to support financial security and mental health.
• Annual performance bonus, equity, or other incentive compensation may be available, as applicable.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior