Alejo Castillo González

Email: alejoworkstuff@gmail.com | Phone: +54 9 221 613‑3317 | LinkedIn: linkedin.com/in/alejo-castillo-gonzalez | GitHub: github.com/alejosworkstuff

Portfolio: alejosworkstuff.github.io/portfolio | Location: La Plata, Buenos Aires, Argentina

Alejo Castillo profile photo

Professional Summary

AI-focused Fullstack Developer building user-facing apps with Next.js (App Router), TypeScript, and Vercel. I ship with typed APIs (Zod/TypeScript), HTTP timeout/retry plus deterministic fallbacks, and CI/CD so failures fall back cleanly. Recent work: a client CMS (Clerk, Prisma, Blob), ExportOps (Argentina monotributo fiscal runway), streaming AI with the Vercel AI SDK, and ecommerce flows covered by Playwright E2E.

Technical Skills

Professional Experience

Freelance Full-Stack Developer: Saravá Radio Streaming

  • Delivered and continue evolving a multi-page cultural community site (Next.js App Router, TypeScript, Tailwind) as a paid client commission.
  • Built a single-admin CMS with Clerk, Neon/PostgreSQL + Prisma, and Vercel Blob so the client manages posts, media, and site logo without code deploys.
  • Shipped reader comments, a featured-content hero, and CI/CD on Vercel for repeatable releases.

Projects

AI Story Generator

  • Built a streaming LLM story product on Vercel serverless routes with Vercel AI SDK (streamText) and Groq (Llama 3.3).
  • Added Zod validation, per-IP rate limiting, CSP headers, resilient HTTP, and deterministic local fallbacks when the provider fails.
  • Wired GitHub Actions CI/CD and Playwright E2E; RAG over pgvector and an eval harness are in progress.

ExportOps

  • Built a cockpit for Argentinian freelancers exporting services: USD/EUR ledger → ARS at BNA seller FX and a rolling 12-month runway vs monotributo ceiling.
  • Next.js App Router, TypeScript, Tailwind, Clerk, Neon/PostgreSQL + Prisma; clients CRUD linked to income entries.
  • In-app alerts at 80%/95% of ceiling plus recategorization window (Jan/Jul); deployed on Vercel.

mini-ecommerce

  • Shipped catalog, cart, checkout, and orders on Next.js App Router with Clerk auth and protected routes.
  • Reduced catalog load risk with SSG/ISR and a typed HTTP client (timeout/retry); Redis cart sync and Prisma + PostgreSQL for orders.
  • Added Sentry error boundaries, Vitest/Testing Library coverage, and Playwright checkout E2E in GitHub Actions CI/CD.

Mini Job Board

  • Built a responsive job board in vanilla JavaScript (search, multi-filter, sorting, saved jobs) with localStorage persistence to prove solid DOM/HTML/CSS fundamentals.
  • Added CI/CD with syntax checks, JSON schema validation, unit tests, and Playwright E2E so core user flows stay reliable under iteration.

Education