ELI CRISTOBAL

Full-Stack Product Engineer · LLM-Native Builder · Idea → Production, Solo

Fresno, CA · infomomtelo@gmail.com · runp8.com

Founder who has shipped six LLM-native SaaS products to production solo — no PM, no designer, no architect. Claude API in production every day: prompt design, model fallback strategies, usage metering, vision workflows, and cost controls. I talk directly to my users, iterate in days, and own everything from schema design to Stripe webhooks to marketing.

Experience

• Shipped 6 production LLM-native products 0→1, solo: Title22 (AI compliance for residential care facilities), RentyApp (property management with Claude vision inspections), OwnSite (AI website builder), TheJudgy (AI dispute mediation incl. live two-party sessions), iGuide (AI build guides), PostPilots (AI social content).
• AI-native workflows in production: prompt engineering across products, Haiku→Sonnet model fallback for cost/quality tradeoffs, vision API for real-world document and photo analysis, structured JSON outputs, per-plan usage metering with fail-closed credit deduction.
• Platform architecture, decided independently: unified auth + cross-app AI credit system on Supabase (Postgres, RLS, Realtime); dual-project data isolation; hardened Stripe webhooks with price-ID filtering after diagnosing and fixing a cross-app contamination bug.
• Direct user engagement: built Title22 hand-in-hand with a working RCFE administrator; RentyApp shaped by my own property management operations; rapid iteration from direct user feedback.
• Ship velocity: prototype to production in days on Cloudflare Workers/Pages; full billing loops (checkout, webhooks, customer portal) implemented and hardened per product; mobile-first PWA delivery.
• Full ownership: product decisions, scope cuts, architecture, security fixes, growth (organic TikTok + SEO) — the complete loop of building and operating software people rely on.

• Hands-on operational experience in regulated, people-centric industries — the perspective behind building compliance and workflow tools that practitioners actually use.

Technical Skills

• AI/LLM: Anthropic Claude API (Messages, vision, streaming), prompt engineering, model selection & fallback, usage/credit systems, structured outputs
• Stack: JavaScript, React/Vite, Node.js, SQL; Cloudflare Workers & Pages; Supabase (Auth, Postgres, RLS, Realtime); Stripe; GitHub; OAuth; Resend
• Product: 0→1 scoping, mobile-first design, PWA, SEO, content-led growth

Licenses & Certifications

• RCFE / CBRC Administrator (California)
• Licensed Property Manager
• Certified Home Inspector

Live Portfolio

• title22.app · rentyapp.net · thejudgy.com · runp8.com — all live, all revenue-instrumented, all built solo.