Strong technical background in AI and clear startup mindset, but lacks direct experience building and operating production backend infrastructure, which is a strict requirement from the founders.
Impressive early-career AI engineer, but does not meet the bar for this level. Strong in agentic AI and cloud application development, but lacks depth in production infrastructure ownership.
Strong engineering background but experience is primarily focused on R&D and hardware, which doesn't align with our current needs.
Seniority mismatch: needs to have at least 3+ years of relevant experience.
Tweets, press, and people that show why this team is worth your time.
Kastle is hiring Members of Technical Staff — internally referred to as founding engineers. The mandate is to architect and own the core systems that power Kastle's real-time AI voice and compliance workflows for top-10 US mortgage lenders. Someone who's a little bit more infra / backend.
The archetype is the engineer who comes in, has an opinion on how the product should actually be built, and starts rebuilding it.
What You'll Own
- Architect and own core systems that power real-time AI voice and compliance workflows
- Push performance boundaries — sub-700ms latency via event-driven architecture and parallel processing
- Deploy, operate, scale resilient systems using Kubernetes and distributed sub-systems
- Build a self-improving AI system that improves with every customer interaction and human feedback
- Ship fast, ship right — whiteboard design to live production in bank environments
- Set engineering culture and best practices — code reviews, docs, architecture decisions
Requirements
- 3+ years professional engineering experience
- Strong Python fundamentals
- Strong backend + infrastructure depth — has personally architected production backends, not just shipped within someone else's stack
- Deep understanding of distributed systems, reliability, fault tolerance
- Excellent database design and performance optimization
- Strong opinions on architecture with bias to defensibly rebuild what's wrong
- Bias for ownership — figures things out in messy, high-velocity environments
- SF-based or willing to relocate immediately — 5 days/week
- Cracked with AI tooling — Claude / Cursor / Codex daily
- Genuine interest in mortgage / lending space — documented failure mode
- Visa: H-1B transfer OK, TN OK (no OPT; O-1 too slow)
Profile Tier 1 — Distributed Systems / Low-Latency Backend at High-Bar Companies
- AWS distributed systems / low-latency teams
- Palantir Foundry infrastructure / platform teams
- Databricks, Snowflake compute layer / infra
- CockroachDB, MongoDB, Confluent, Vespa, Pinecone, Weaviate, Elastic, Clickhouse, Materialize, Neon, PlanetScale, Convex, Supabase infra
- Verkada — direct culture and technical match
Tier 2 — AI Infrastructure / Voice Infrastructure Engineers
- Anthropic Applied / Production Infra, OpenAI Solutions / Production Infra, Together AI, Fireworks AI, Modal, Replicate, Anyscale, Cohere infra
- Voice infra: Deepgram, Cartesia, ElevenLabs infra, Retell, Vapi, Bland, Air.ai, PolyAI, HappyRobot
- Twilio infra, Vonage infra
- Real-time / sub-second production systems
Tier 3 — Ex-YC Founding Engineers with Backend Depth
- YC founders and founding engineers of companies with real backend architecture. Especially data-intensive or infra-heavy YC products
Tier 4 — Impressive Fast-Moving Startups with Real Infra
- Perplexity, Cursor, Vercel, Modal, Replicate infra teams
- Mercor, Weap, Sierra, Decagon, Glean, Cresta infra
Tier 5 — Compliance-Heavy Vertical AI Infrastructure
- Harvey, Eve, Spellbook — legal AI infrastructure
- Blend, Ocrolus, Truework, Snapdocs, Rocket Companies — mortgage / lending infra
Tier 6 — Big Tech Infrastructure with Zero-to-One Signal
Strong Bonuses
- Kubernetes production experience
- Event-driven architecture, parallel processing
- Sub-second latency systems — voice AI, HFT, ad-serving, real-time bidding, real-time recommendation
- AWS distributed systems
- Verkada alumni
- Compliance-heavy production systems — FDCPA / RESPA / TILA / HIPAA / SOC 2 / PCI
- Voice / telephony / real-time media infrastructure
Location and Visa
- H-1B transfer OK, TN OK, OPT is a hard no, O-1 acceptable