Hello, I'm
Andrés Castillo
I build performant, scalable web applications and integrate AI-driven solutions to solve complex real-world problems and deliver exceptional user experiences.
About Me
Engineering intelligent, scalable web experiences.
I'm a Web Architect who designs end-to-end systems across diverse industries and complex business domains. My work sits at the intersection of modern web engineering and AI — not as separate disciplines, but as a unified approach to building smarter software.
I specialize in turning complex business problems into clean, maintainable architectures — increasingly enhanced by AI-assisted development workflows. Beyond code, I invest in growing engineering teams through technical leadership, community building, and hands-on mentoring.
12+ years experience Medellín, Colombia
Skills & Tools
Technologies I Work With
I believe in choosing the right tool for the job. Here are the technologies I use most frequently.
AI & Intelligent Systems
- Prompt Engineering
- RAG / Embeddings
- LLM Integration (Claude, OpenAI)
- Ollama / Local Models
- pgvector
- AI-Assisted Development (Cursor, Claude Code)
Frontend
- React / Next.js
- Svelte / SvelteKit
- Vue.js / Nuxt
- JavaScript / TypeScript
- Tailwind CSS
- HTML5 / CSS3
Backend
- Node.js
- NestJS
- Python / Django
- Go
- REST & GraphQL
- WebSockets
Database
- PostgreSQL
- MongoDB
- Redis
- Prisma / Drizzle
- MySQL
- Supabase
Cloud & DevOps
- AWS / GCP
- Docker
- CI/CD Pipelines
- Vercel
- Terraform
- GitHub Actions
Selected Work
Projects I've Built
Each project represents a unique challenge. I focus on clean code, performance, and delivering real value.
BarrioAlerta
In Development
Neighborhood safety app for Colombian cities that replaces chaotic WhatsApp security groups with a structured incident map, verified neighbor network, smart proximity alerts, and weekly barrio safety trends.
React Native Node.js PostGIS Firebase
CargaCO
In Development
Colombia's unified EV charging platform. Aggregates fragmented charger networks into a single live map with real-time availability, reservations, and COP-native payments via Nequi and PSE. Includes a B2B CPO dashboard for malls, hotels, and parking operators to monetize their chargers with dynamic pricing and utilization analytics.
React Native Next.js Node.js PostgreSQL OCPP
// latest posts
From the Blog
Thoughts on development, design, and building better software.
Claude Code AI Agents
Claude Code Skills at Scale: Lessons from Anthropic's Own Team
Anthropic runs hundreds of Claude Code Skills internally. Here's what they learned — 9 skill types, what makes them actually work, and how to build yours.
March 19, 2026 9 min read
AI Architecture
MCP Won. Here's What It Means for Your Architecture
Model Context Protocol went from Anthropic side project to industry standard in under a year. OpenAI, Google, Microsoft, Databricks — everyone adopted it. Here's why it won, how it works, and what you need to change today.
March 18, 2026 10 min read
AI Career
The Developer Is Not Dead. But the Role Is Changing Fast.
NYT says AI is ending programming as we know it. I've been coding for 12 years. Here's what I actually think is happening.
March 17, 2026 6 min read
Contact
Let's Work Together
Have a project in mind or just want to chat? Drop me a message and I'll get back to you as soon as possible.
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Connect
Currently open to freelance opportunities and exciting full-time roles. Available for remote work worldwide.