# AppSimple LLC

> Applied AI Engineering, Founder-Led

- Canonical listing: https://agencysource.com/agencies/appsimple
- Categories: [Custom Software Development](https://agencysource.com/categories/custom-software-development), [AI Agents & Automation](https://agencysource.com/categories/ai-agents-automation), [AI & LLM Development](https://agencysource.com/categories/ai-development), [Mobile App Development](https://agencysource.com/categories/mobile-app-development)
- Services: Generative AI, AI Agents, AI Development, Mobile App Development
- Team size: Freelancer
- Hourly rate: $100 - $149 / hr
- Minimum project: $10,000+
- Founded: 2013
- Website: https://appsimple.io
- Listing: Not yet claimed
- Agency Source rating: no Agency Source reviews yet

## About

AppSimple is the applied-AI studio of Charles Feinn — a senior engineer with 12+ years of experience and an M.S. in AI/ML. I help startups and established businesses turn large language models into real, dependable products, not throwaway demos.

What I build:

- AI & LLM integration — adding generative AI to existing products and workflows
- AI agents and agentic systems — tools that plan, retrieve, and act

Document understanding & data extraction — turning unstructured PDFs, images, and text into structured data

Production backends — FastAPI services, cloud deployment, evaluation, and monitoring that keep AI features reliable

I also design and ship native iOS apps end to end when a product needs one, backed by 12+ years of Apple-platform experience.

How I work:

You work directly with me — the person actually building your software. No account managers, no handoffs to junior teams. I combine modern AI-assisted ("agentic") development to move quickly with disciplined evaluation, testing, and monitoring, so what you ship is production-grade and maintainable.

Who I work with:

Founders and product teams who need senior AI engineering without staffing a full in-house team — from a fast LLM proof-of-concept to a deployed, monitored system.

Let's turn your idea into working, reliable software.

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