---
title: 'Infrastructure Engineer at Kastle'
canonical: 'https://feeny.ai/job/infrastructure-engineer-kastle-san-francisco-4jrgv0j9v7rc'
type: 'job'
last_seen: '2026-11-07'
---

# Infrastructure Engineer at Kastle

- **Company:** Kastle
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-11-04
- **Last confirmed live:** 2026-11-07
- **Apply:** https://jobs.ashbyhq.com/Kastle/7f0955a9-335d-49f7-937f-7f4563a688d1

## Job description

Kastle is building the AI employee for financial services. We work with some of America's largest banks, helping them scale their operations using autonomous AI Agents that process payments, originate loans, and help customers get a world class experience during some of the biggest financial decisions of their lives. We've processed over $2 billion in transactions and are backed by Insight Partners and Y Combinator. If you are interested in building AI that is applied in the real world where precision, reliability, and performance matter and redefine access to credit across the world, apply below.

We just raised a $24M Series A and are growing fast!

What We’re Looking For:

At Kastle our Infrastructure team is responsible for building the underlying systems that help thousands of people daily, make their largest and most important financial transactions. We're looking for a Senior Infrastructure Engineer with deep distributed systems expertise to design, build, and operate the infrastructure that powers Kastle's AI agents in production at banks, lender and other financial institutions. You'll work on the hard problems of distributed systems — consistency, fault tolerance, horizontal scalability, and low-latency coordination — across AWS/GCP/Azure, Kubernetes, and Terraform, keeping compliance-critical systems reliable as we grow. This is an onsite role working closely with platform, ML, and security engineering.

What You’ll Do:

- Design and operate distributed systems that power AI agents in production, with an emphasis on consistency, fault tolerance, and horizontal scalability
- Architect service-to-service communication, coordination, and state management for systems spanning multiple regions and availability zones
- Own Kubernetes cluster architecture, scaling, and security hardening across environments
- Build and maintain Terraform modules and GitOps pipelines so infrastructure changes are reviewed, versioned, and repeatable
- Design for the reliability and auditability bar that regulated financial institutions require: replication, failover, backups, disaster recovery, and change logs
- Diagnose and resolve distributed-systems failure modes — network partitions, cascading failures, split-brain scenarios, race conditions — under production pressure
- Build observability (metrics, distributed tracing, logging, alerting) so the team can see problems before customers do
- Partner with ML, platform, and security engineering on capacity planning, data consistency guarantees, and architecture reviews
- Participate in an on-call rotation for production infrastructure
- Mentor other engineers on distributed systems design and review their architecture and IaC changes

What We’re Looking For:

- 5+ years in infrastructure, platform, or backend engineering roles, with substantial hands-on distributed systems experience
- Strong understanding of distributed systems fundamentals: consensus, replication, partitioning, consistency models (CAP/PACELC), and failure modes
- Production experience with at least one major cloud provider (AWS, GCP, or Azure) at scale
- Hands-on experience running Kubernetes in production, including cluster upgrades, networking, and security policy
- Experience designing or operating distributed data stores, message queues, or event streaming systems (e.g. Kafka, etcd, Cassandra, CockroachDB)
- Strong background in infrastructure-as-code (Terraform preferred) and CI/CD pipelines
- Proficiency scripting/programming in at least one language (Go, Python, or Rust) for building distributed tooling
- Experience owning production reliability: on-call, incident response, postmortems
- Comfortable working onsite and collaborating closely with product, ML, and security teams

## About Kastle

## Core Business
- **Primary industry**: Consumer lending / Mortgage servicing technology (Fintech)
- **Target customers**: FDIC-insured banks, independent mortgage banks (IMBs), and large consumer lenders (B2B, Enterprise)
- **Mission or purpose statement**: To help traditional financial services companies better interface with their customers by automating high-volume phone calls with compliant AI agents.

## Products & Services
- **Avery (Servicing Agent)**: AI voice agent that handles borrower inquiries, payment collection, escrow questions, and loss mitigation. Integrates with ICE’s MSP system.
- **Collections Agent**: Automates payment reminders, engages delinquent borrowers early, and recovers past-due accounts.
- **Compliance Agent**: Monitors and scores every interaction against regulations (FDCPA, TILA, UDAAP, RESPA, TCPA) for 100% QA coverage.
- **Loan Officer Assistant**: Qualifies new loan inquiries and automates pre-qualification calls.
- **Sentinel (QA & Compliance Agent)**: Real-time monitoring and automated scorecards for borrower calls and servicing documentation.
- **Agent Builder**: Allows lenders to turn SOPs into AI agents using natural language, with no-code configuration.
- **Platform features**: Omnichannel support (voice, SMS, email, chat), simulation testing, transparent observability, and integration with existing contact center, payment processor, and LMS systems.

## Market Standing
- **Valuation**: Not disclosed (private startup)
- **Key Metric**: Total funding of $510,000 (Pre-seed round led by Y Combinator, June 2024)
- **Notable Investors/Partners**: Y Combinator (lead), ICE Mortgage Technology (integration partner)
- **Growth Signals**:
  - Headcount: 10 employees (+66.7% YoY)
  - Won LendingTree’s 2024 Innovation Challenge (Nov 2024)
  - Featured in a16z’s February 2025 fintech newsletter on voice AI
  - Integration with ICE’s MSP servicing system (April 2026)
  - Most deployed AI voice agents in the mortgage industry (per website)
  - Active job postings: 8 positions, with 300% yearly increase in listings

## Competitive Advantages
- **Purpose-built for compliance**: Pre-trained on key lending regulations (FDCPA, TILA, UDAAP, RESPA, TCPA) with a proprietary Compliance Engine.
- **Enterprise-grade integrations**: Direct connectivity with ICE’s MSP (the dominant mortgage servicing system) and other core systems.
- **Fast time to value**: Go-live in days with out-of-the-box agents that map to existing workflows.
- **Transparent AI**: All responses are fully explainable with built-in reasoning, enabling audit-ready operations.
- **Battle-tested track record**: Claims to have the most deployed AI voice agents in the mortgage industry, with proven metrics (70% lower cost per call, 40% lower handle time, 90%+ CSAT).

## Strategic Focus
- Deepening integrations with core mortgage systems (e.g., MSP) to reduce friction for large lenders.
- Scaling the AI agent workforce across the full lending lifecycle (origination, servicing, collections, compliance).
- Expanding from voice to true omnichannel (SMS, email, chat) and adding more pre-built agent types.
- Growing the enterprise customer base among FDIC-insured banks and IMBs.

## Why Work Here
- **Culture**: Early-stage YC startup with a small, high-agency team (10 people). Founders have strong product/engineering backgrounds (Redfin, Verkada). Emphasis on building mission-critical AI for a regulated industry.
- **Work policy**: Based in San Francisco (185 Channel Street). Likely in-office given the early stage and need for close collaboration.
- **Notable perks/engineering culture**: Opportunity to work on proprietary inference technology, compliance engine, and real-time AI systems. Roles span applied AI, forward deployment, and product management. High ownership and impact from day one.
- **Growth trajectory**: Rapid headcount growth (66% YoY), multiple open roles, and strong market traction suggest significant career growth potential.

## Sources
1. [kastle.ai](https://www.kastle.ai/)
2. [ycombinator.com](https://www.ycombinator.com/companies/kastle)
3. [linkedin.com](https://www.linkedin.com/company/kastleai)
4. [cbinsights.com](https://www.cbinsights.com/company/kastle)
5. [ycombinator.com/jobs](https://www.ycombinator.com/companies/kastle/jobs)

## Other roles at Kastle

- [Technical Lead, SWE](https://feeny.ai/job/technical-lead-swe-kastle-san-francisco-8y3t3e3451td) — San Francisco, CA
- [Head of Deployments](https://feeny.ai/job/head-of-deployments-kastle-san-francisco-bmbbj6fdx85v) — San Francisco, CA
- [Events and Experiences Lead](https://feeny.ai/job/events-and-experiences-lead-kastle-san-francisco-dgeh3yg0bdnw) — San Francisco, CA
- [Compliance and Legal Counsel](https://feeny.ai/job/compliance-and-legal-counsel-kastle-san-francisco-t19sgkg49pvz) — San Francisco, CA
- [Enterprise Account Manager](https://feeny.ai/job/enterprise-account-manager-kastle-san-francisco-rjxfn826wsp7) — San Francisco, CA
- [Head of Talent](https://feeny.ai/job/head-of-talent-kastle-san-francisco-nha1c45z3qe5) — San Francisco, CA
- [GTM Recruiter](https://feeny.ai/job/gtm-recruiter-kastle-san-francisco-c8ncandzsw4h) — San Francisco, CA
- [Founding Growth Lead](https://feeny.ai/job/founding-growth-lead-kastle-san-francisco-gfsm4jdn94mp) — San Francisco, CA
- [Head of Sales](https://feeny.ai/job/head-of-sales-kastle-san-francisco-n59cy1gvy827) — San Francisco, CA
- [Senior Product Manager](https://feeny.ai/job/senior-product-manager-kastle-san-francisco-6tpnpyev1a7f) — San Francisco, CA