I build scalable products
from architecture to production.

$ scroll down ↓

$ ls ~/skills

TypeScript
React
Next.js
TanStack Start
shadcn/ui
Node.js
NestJS
Golang
.NET
Bun / Elysia
Fastify
Ruby on Rails
LLM Integration
RAG Pipelines
Vector Search
AWS
Docker
PostgreSQL
MongoDB
Redis
Git

$ ls ~/projects

Open-source explorations in distributed systems, AI pipelines, and concurrency.

Full-Stack01

Task Management System

A microservices-based task management platform with real-time collaboration. Multiple services communicate through RabbitMQ, enabling async workflows and loose coupling. Features WebSocket-powered live updates and a React frontend with optimistic UI.

  • Microservices architecture with API Gateway
  • Event-driven async communication
  • Real-time WebSocket updates
Node.jsNestJSRabbitMQPostgreSQLWebSockets+2
AI / Data02

News Agent RAG

An AI-powered information retrieval system using Retrieval-Augmented Generation. Ingests news articles, processes them through LLMs, stores vector embeddings, and enables semantic querying. Kafka handles stream ingestion for real-time processing.

  • End-to-end RAG pipeline
  • Kafka streaming ingestion
  • LLM-powered semantic search
Node.jsTypeScriptOpenAIKafkaMongoDB+1
Product03

TuneSync

A playlist converter that moves music between streaming platforms like Spotify and YouTube. Explores complex OAuth flows, third-party API integrations, and music metadata matching algorithms across different catalog systems.

  • Multi-platform OAuth integration
  • Cross-catalog music matching
  • Product-focused UX design
Next.jsReactTypeScriptSpotify APIYouTube API+1
Systems04

Go Event Counter

A backend event-processing service built to explore Go concurrency primitives. Simulates high-throughput event handling using goroutines, channels, and worker pool patterns with minimal overhead.

  • Go concurrency model deep-dive
  • Worker pool pattern
  • Race-condition-safe design
GoGoroutinesChannels
$ git log --graph --oneline --all
HEAD → main
a3f7c21

Contract Project (Education Platform)

Full-Stack Engineer

Sep 2025 — Present

Joined a 3-engineer team to build an education platform from scratch in 2 months, replacing a third-party solution. Defined the frontend architecture and contributed across the full stack.

01Defined frontend architecture with TanStack Start, React, and TypeScript — structuring componentization, routing, and performance patterns
02Designed and built a reusable design system with shadcn/ui, improving visual consistency and development speed
03Contributed to the backend with .NET, PostgreSQL, and Redis — data modeling and REST API integration
04Delivered a production platform now serving 15,000+ users with stability under continuous growth
● merged into main
e82d4b9

AlfaCon

Full-Stack Engineer

Jun 2023 — Aug 2025

Worked on the core product team of Brazil's largest competitive exam prep platform, building AI-powered features and full-stack solutions serving 5M+ users.

01Built an internal chatbot with LLMs and RAG for automated lead qualification, achieving 60% adoption by the sales team
02Implemented AlfaQuiz platform with AI-driven dynamic question generation, increasing student engagement by 40%
03Integrated AI features into the virtual learning environment used by 5M+ users, reducing operational overhead
04Contributed full-stack features across Ruby on Rails, Next.js, Node.js, and NestJS
● merged into main
initial commit

$ cat services.json

How do I charge?

Transparent tiers, no surprises. Hover to decode pricing — or skip straight to a conversation.

tier 1

Landing Page

Single page, responsive, SEO optimized. Perfect for product launches and personal brands.

  • [x]Design & Development
  • [x]Responsive & Mobile-first
  • [x]SEO Optimization
  • [x]Deployment & Hosting
$ get --quote

tier 2

Full-Stack Application

Complete web application with frontend, backend, database, and deployment pipeline.

  • [x]Everything in Landing Page
  • [x]Authentication & Authorization
  • [x]REST / GraphQL API
  • [x]Dashboard & Admin Panel
  • [x]CI/CD Pipeline
$ get --quote
recommended

tier 3

AI Integration

LLM integration, RAG pipelines, AI-powered chatbots and intelligent automation.

  • [x]Everything in Full-Stack
  • [x]LLM Integration (OpenAI, Claude)
  • [x]RAG Pipeline & Vector Search
  • [x]AI Chatbots & Agents
  • [x]Fine-tuning & Evaluation
  • [x]Production Monitoring
$ get --quote

tier 4

Enterprise

Custom scope, architecture consulting, and dedicated support for complex projects.

  • [x]Everything in AI Integration
  • [x]Architecture Design & Review
  • [x]Technical Consulting
  • [x]Dedicated Support Channel
  • [x]Custom SLA & Scope
  • [x]Team Training & Handoff
$ get --quote

$ ssh colman@colman.dev.br

Have a project in mind?
Let's build something together.

$ cat > message.txt