Staff AI Engineer

About the Company

Kastle is building an AI operating system for consumer lending, starting with mortgage. Backed by Y Combinator and Commerce Ventures, we work with some of America's largest mortgage lenders to scale contact center and compliance operations using AI-driven voice agents.

Responsibilities

• Fine-tune and deploy LLMs for real-time voice-based borrower interactions
• Design and iterate on prompt strategies to optimize AI performance and compliance
• Build high quality evals using proprietary datasets to benchmark AI agent performance
• Train and implement domain-specific AI models for consumer lending
• Ensure AI solutions meet regulatory standards and scale efficiently
• Build robust AI-driven workflows and data pipelines that integrate with loan servicing platforms
• Monitor performance metrics and continuously improve agent quality

Requirements

• 2+ years building and deploying ML/AI systems in production environments
• Strong proficiency in Python and deep learning frameworks like TensorFlow or PyTorch
• Experience with LLM orchestration frameworks such as LangChain or LlamaIndex
• Proven track record of shipping AI products used by real users
• Strong product mindset and ability to translate business requirements into AI solutions
• Excellent communication skills for cross-functional collaboration

Benefits

• Competitive salary
• Meaningful early-stage equity
• Relocation support