Boutique software engineering · Since 2004

Production AI for companies that already have a product.

Agentic automation, legacy upgrades, and fractional CTO leadership from a senior engineer with 25 years in production — forward-deployed with your team, fixed-scope, no handoffs.

Who we work with

Our clients already run real software — a Rails, Python, or Node application with customers, data, and a roadmap. They need senior engineering to add AI that holds up in production, modernize what's aging, and make technology decisions with someone who has been on the hook for production before. That is what Layer 3 does.

Services

What we do

Senior engineering, scoped and priced up front.

Agentic Automation

Multi-step business processes handled by agents that hold state, verify their own work, and escalate when they should.

  • Agent & workflow design
  • Memory, retrieval & learning loops
  • Evals, guardrails & observability

Fractional CTO

Technology leadership without the full-time hire: roadmaps, architecture, AI and vendor strategy, and hiring, from someone who has run production systems rather than only reviewed them.

  • Technology strategy & roadmapping
  • System & AI architecture
  • Technical hiring & team leadership

Product Engineering

Full-stack development from concept to deployment — Rails, Python, Node, and React — with the DevOps to keep it running.

  • Full-stack development
  • UX & prototyping
  • DevOps, CI/CD & cloud
Why Layer 3 Development

Founder-led, production-first

Layer 3 Development is led by Shawn Cunningham, a senior engineer who has built and operated production systems across fintech, legal tech, healthcare, and hospitality since 2004. Clients have included Prosper, Shangri-La Hotels, and The Melt.

25+ years shipping and operating production software
Building agentic systems on Claude and the Anthropic SDK daily
Forward-deployed: we embed with your team, not throw code over the wall
Fixed-scope engagements with milestone checkpoints — no open-ended hourly surprises
Security-first: HIPAA and SOC 2 experience
The engineer you talk to on the first call is the engineer who does the work

Expertise

Where we go deep

AI & Agent Systems

LLM agents, retrieval (RAG), evals, and model routing built into production applications.

SaaS Applications

Custom SaaS solutions built with modern tech stacks, advanced authentication, subscription management, and multi-tenant architectures.

Data Engineering

Scalable data pipeline design, ETL processes, analytics platforms, and business intelligence solutions with modern data stacks.

Security Engineering

Application security architecture, vulnerability assessment, compliance implementation, and secure coding practices in modern applications.

DevOps & Cloud

Infrastructure as code, CI/CD pipeline automation, cloud-native architecture, and containerization strategies for modern deployments.

IoT Systems

Connected device ecosystems with real-time data processing, edge computing capabilities, and secure cloud integration.

Get in touch

Fifteen minutes is enough to know whether we can help. Book a call, or send a note.

Contact Information

Location

San Francisco, CA

Remote-first, on-site when it matters

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