David RENGIFO — Portfolio

LLM Copilot

● Live GitHub →

Production AI copilot with 3 NLP tools: customer feedback analysis, document summarization (PDF support up to 100k chars), and structured entity extraction. Multi-step prompt engineering with Pydantic schema validation on every LLM response.

Backend FastAPI Python Pydantic v2 slowapi

AI GPT-4o-mini Prompt Engineering JSON mode

Frontend React 19 TypeScript Vite 8 pdfjs-dist

Deploy Railway Vercel davrengifo.dev

💬

Feedback Analysis

Sentiment, themes, priority KPIs, executive summary

📄

Document Summary

Key points, decisions, actions — PDF drag & drop

🔍

Entity Extraction

Dates, names/orgs, monetary amounts structured as JSON

🛡️

Cost Controls

Rate limiting · 100k input cap · 1500 token output cap

46

Tests

3

NLP tools

3

Languages

20 req/min

Rate limit

CoinsProphet

● Live GitHub →

Production crypto RAG platform: real-time data pipeline (price + news), semantic search engine via pgvector, daily AI-generated reports, and a responsive React dashboard. 10 microservices orchestrated with Docker Compose on GCP.

Backend FastAPI Python 8 REST endpoints Redis TTL cache

AI / RAG GPT-5.4-mini text-embedding-3-small pgvector HNSW 1536 dims

Data PostgreSQL 16 pgvector Redis queue Playwright

Frontend React 18 Recharts ReactMarkdown

Infra Docker Compose GCP e2-micro Nginx + HTTPS GitLab CI/CD

RAG Pipeline

News + Prices → Redis queue → Worker → Embeddings (1536d) → pgvector HNSW → cosine top-k → GPT-5.4-mini → Response + sources

price_collector

CoinGecko API · 8 tokens · every 5 min

news_collector

3 RSS feeds · every 15 min

scraper

Playwright · CoinMarketCap fallback

worker

Redis → PostgreSQL → embeddings

api

FastAPI · prices, history, news, /ask

report_generator

Daily AI report at 08:00 UTC

frontend

React 18 SPA · Nginx static

nginx

Reverse proxy · HTTPS Let's Encrypt

postgres

pgvector · HNSW cosine index

redis

TTL cache + async queue

10

microservices

8

tokens tracked

480+

embeddings

450+

news articles

Harbor — Activity Marketplace

● Live GitHub →

Full-stack activity booking marketplace built with Next.js 16 App Router. Discover local experiences, filter by category and location, save favourites, book activities, and simulate checkout — with server-side rendering, Redis caching, and GitHub OAuth.

Frontend Next.js 16 React 19 TypeScript Tailwind CSS 4 Leaflet

Backend Prisma 6 PostgreSQL Redis (Upstash) API Routes

Auth Auth.js v5 GitHub OAuth

Tests Jest Playwright

Deploy Vercel Neon (PG)

🗺️

Interactive Map

Leaflet map with activity pins, filter by category & location

❤️

Favourites

Persisted favourites via API, protected by auth

📅

Booking Flow

Reservation creation, tracking, simulated checkout

⚡

Redis Cache

Versioned cache keys · short TTL activities, long TTL filters