Kastle Systems International

Kastle Systems International

Staff AI Engineer

San Francisco · Staff+

Sponsorship not specifiedDetected 242 days ago
Machine LearningData EngineeringLLMsCommunication

About the role

  • As a Founding Applied AI Engineer, you'll be instrumental in building the technical foundation of Kastle's AI platform. You'll fine-tune large language models, design AI workflows for highly regulated enterprises, and ensure our voice agents deliver precise, compliant, and effective borrower interactions.
  • This role is ideal for an engineer who is passionate about applied AI, eager to solve real-world challenges, and excited to build the technical foundation of an early-stage AI startup.
  • As a Founding Applied AI Engineer, you'll be instrumental in building the technical foundation of Kastle's AI platform.

Responsibilities

  • Prompt Engineering: Design and iterate on prompt strategies to optimize AI performance and compliance
  • Evaluate LLMs and AI Agents: Build high quality evals using our proprietary datasets to benchmark AI agent performance and run experiments
  • Custom AI Solutions: Train and implement domain-specific AI models for consumer lending
  • Data Pipelines & APIs: Build robust AI-driven workflows that integrate seamlessly with loan servicing platforms
  • 2+ years building and deploying ML/AI systems in production environments
  • Excellent communication skills to collaborate across product, engineering, and compliance teams
  • Design and iterate on prompt strategies to optimize AI performance and compliance

Requirements

  • Experience with LLM orchestration frameworks (LangChain, LlamaIndex, or similar)
  • Track record of shipping AI products that real users depend on
  • Strong product mindset and ability to translate business requirements into AI solutions

Compensation

  • Strong upside: Competitive salary, meaningful early-stage equity, and relocation support

Benefits

  • Competitive salary, meaningful early-stage equity, and relocation support
  • Strong proficiency in Python and deep learning frameworks (TensorFlow, PyTorch)

Company info

  • Kastle is building AI operating system for consumer lending, starting with mortgage.
  • We work with some of America's largest mortgage lenders, helping them scale their contact center and compliance operations using AI-driven voice agents.
  • Backed by Y Combinator, Commerce Ventures, and executives from Snapdocs, Google, and WePay, we are redefining lending with AI.
  • High ownership and autonomy with direct input on product, technical direction, and company culture

This listing is sourced directly from Kastle Systems International's careers page and normalized into a canonical job model.