Founding Engineer at Kastle

About Kastle

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 voice agents. Backed by $2.3M from Y Combinator, Commerce Ventures, and executives from Snapdocs, Google, and WePay, we are redefining lending with AI.

About the Role

We’re looking for a Founding Engineer to build and optimize the Kastle platform. As an early team member, you’ll have a pivotal role in architecting and scaling our AI systems, ensuring high availability, low latency, and compliance with strict financial regulations.

You’ll work closely with the founding team to design, develop, and deploy mission-critical AI applications that integrate with financial institutions. This role requires expertise in backend development and LLM Engineering—ideal for an engineer who thrives in high-impact environments.

Responsibilities

Architect and develop scalable backend services for AI-driven consumer lending applications.
Design and implement APIs that integrate with loan servicing platforms, payment processors, and compliance systems.
Optimize performance for real-time AI interactions, ensuring sub-700ms latency.
Manage containerized deployments using Kubernetes to maintain high availability and reliability.
Develop event-driven architectures using Python AsyncIO for parallel processing and real-time automation.

Kastle is an AI voice agent for mortgage servicing. We help servicers collect payments, verify new borrowers, and qualify new loan inquiries over the phone.

Rishi and Nitish met at UIUC where they graduated with degrees in systems engineering and computer science. Rishi was the founding Product Manager for Redfin’s Mortgage Marketplace at 22 and grew the business from $3M to $6M in revenue in 9 months. Nitish patented Verkada’s motion search system and was the youngest tech lead at the company at 23.

While building Redfin's Mortgage Marketplace Rishi realized traditional lenders didn't have the infrastructure to service online inquiries and were losing customers. Nitish and Rishi are building Kastle to help traditional financial services companies better interface with their customers.

Founding Engineer at Kastle (S24)

About the role