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Rey L.

Rey L.

Full Stack Web Mobile App AI Developer | 6x AWS & Azure Certified |

I'll help optimize the performance, productivity, and cost expense of your work/team/company/clients by automating tasks, workloads, and projects by integrating various platforms, applications, and systems. Increasing your bottom-line, freeing you time and saving you money. I specialize in building innovative Agentic AI systems and enterprise production grade custom LLM and NLP applications. With expertise in cutting-edge frameworks and tools, I deliver high-impact solutions tailored to your business needs. That's where I come in for you! My related IT-CS background and skills: - 3x AWS Certified (Solutions Architect Associate, Developer Associate, Cloud Practitioner) - 3x Microsoft Azure Certified (Fundamentals, AI, Data) - Python-FastAPI, NodeJS, NestJS Backend Software Engineer (Supabase | Firebase) - Typescript NextJS/React, Angular Frontend Developer - Mobile App Development: Flutter + Firebase; React Native Framework - I also studied Machine learning & Data Science. Low-code, No-code solutions for Micro, Small, & Medium Businesses: - N8N - Zapier - Make (3x Certified - Foundations, Basics, Intermediate) - ClickUp (2x Certified - Expert and Admin) - GoHighLevel (GHL) My Skills and Expertise: • Agentic AI Systems: Architect and engineer advanced systems using LangChain, LangGraph, and other modern frameworks, libraries, and tools like Claude Code, Codex, Cursor, and Antigravity IDE. • Custom AI Applications: Develop powerful AI, LLM, and NLP-driven applications with the OpenAI ChatGPT, Anthropic Claude Opus, Claude Sonnet, Google DeepMind Gemini, and xAI Grok. • Embeddings & Vector Databases: Configure and optimize embeddings and vector databases (e.g., Chroma, Pinecone, Neo4j, Weaviate) for Retrieval Augmented Generation (RAG) workflows. • Advanced RAG Techniques: Engineer RAG and other sophisticated methods to boost model performance and accuracy. • Backend Development: Build and integrate robust Python backend with FastAPI/Django/Flask, manage sessions, data storage and retrieval using various relational (e.g., PostgreSQL, MySQL), non-relational (e.g., MongoDB), and cloud-native databases (Supabase, Firebase, Neon, etc.). • Frontend Development: Create intuitive interfaces using NextJS, React, TypeScript, and Tailwind CSS. • Authentication & Authorization Systems: Implement secure user authentication using OAuth, JWT, or session cookies to ensure security hardening and robust access control. • Payment Integration: Build seamless payment systems with APIs like Stripe, PayPal, or Square for secure, user-friendly transactions. • Email Integration: Develop automated email systems using tools like SendGrid, AWS SES, or Mailgun for notifications, marketing, and user engagement. • Function Calling & Tools: Design and integrate custom tools, function calling, and structured outputs to meet project-specific goals. • Prompt Engineering: Handle AI LLM-NLP prompt engineering, management, and moderation for factual, consistent, accurate, and high-quality outputs. Implement LLM evaluations and observability using eval frameworks to monitor and enhance model performance - Promptfoo, DeepEval, Opik, and Garak. • Cloud Deployment: Deploy scalable web applications to Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform, Vercel, Heroku, etc. Who I Work With: I partner with small and medium businesses, startups, and enterprises, delivering tailored AI solutions that drive results. Whether you need a custom AI application, cloud deployment, or end-to-end machine learning engineering and data science solutions, I’m here to help. Why Choose Me? I put extreme emphasis on integrity, honesty, excellence, impeccable services, and stellar results. If these are the hallmarks that you're after, then we're probably a GREAT fit. With a blend of technical expertise and a client-focused approach, I bring value to every project. My experience spans AI engineering, LLM development, and full-stack development, ensuring versatile and effective solutions. • OpenClaw Personal AI Assistant • Hermes Agent • Microsoft Copilot AI Agents • Google Workspace Developer (Apps Script) • Google Gemini Spark AI Agent [Antigravity ADK] • GoHighLevel (GHL) Automation Engineer • Flutter | React Native Mobile App Developer (Android, iOS) • Web Scraping Full-Stack SaaS AI Automation Developer | Anthropic Claude Code | OpenAI ChatGPT Codex |

🇵🇭Paranaque, Philippines$30/hr100% JSS4.92 (33)Since Oct 2014

Earnings and projects

MRR
$14

Last 6 months ÷ 6

World#169,232 / 412k
🇵🇭Country#25,398 / 56.3k
Revenue, last 30 days
$0

Last 6 months: $87

Total earnings
$132k

Billed in all: $133k

World#28,045 / 412k
🇵🇭Country#3,123 / 56.3k
Per project
$4.9k

$87 in the last 6 months

World#35,688 / 412k
🇵🇭Country#8,418 / 56.3k
Projects, last 6 months
1
0% fixed100% hourly
World#128,095 / 412k
🇵🇭Country#14,297 / 56.3k
Projects in all
27

Across 44 contracts

9% fixed91% hourly
World#106,302 / 412k
🇵🇭Country#7,933 / 56.3k

Earnings, last 30 days

$133kNothing earned in the last 30 daysBilled in all, before Upwork's fee · drag across the chart to see what was earned in any stretch
$130k$132k$134k$136kOct 8Oct 23Nov 7

Skill rankings: Top 34% in React Native

Ranked by MRR among everyone on Upwork with the skill.

  1. #25Product Architecture64 freelancers · 🇵🇭 #1Top 39%
  2. #126Mobile App Improvement281 freelancers · 🇵🇭 #1Top 45%
  3. #221OpenAI Codex409 freelancers · 🇵🇭 #17Top 54%
  4. #306Mobile App Redesign693 freelancers · 🇵🇭 #2Top 44%
  5. #551System Automation1,197 freelancers · 🇵🇭 #52Top 46%
  6. #1,259ClickUp2,407 freelancers · 🇵🇭 #247Top 52%
  7. #1,377Mobile App3,535 freelancers · 🇵🇭 #19Top 39%
  8. #2,600AI App Development4,708 freelancers · 🇵🇭 #20Top 55%