About
I'm Nicolás, a senior full-stack engineer based in Medellín, Colombia (GMT-5). I've spent 12 years shipping React and Node.js products for companies in the US, Sweden and Argentina, and the last few years putting LLMs into products that handle real money and real documents.
I care about the unglamorous parts that make AI features work: schemas, validation, fallbacks, cost tracking, evals and a clear path to a human when the model is unsure.
What I work with
- Frontend: React, Next.js, TypeScript, React Native, micro-frontends
- Backend: Node.js, NestJS, Express, Python/FastAPI, PostgreSQL, REST and GraphQL
- AI: OpenAI, Anthropic Claude and Gemini APIs, structured outputs and tool use, RAG, Claude Agent SDK, MCP servers, evals
- Infra: AWS, GCP, Docker, Terraform, GitHub Actions and GitLab CI
Experience
Tech Lead, Full-Stack · KitchenSync
Accounting automation for US restaurants. Led a team of 4 engineers; integrated QuickBooks, Slack and LLM providers; built a shared TypeScript library used by every service.
Senior Frontend Engineer · Doktor24, Stockholm
Micro-frontend architecture with Module Federation, Node.js BFFs, white-label mobile SaaS, IEC 62304 medical software.
Full-Stack JavaScript Developer · LeoVegas, Sweden
React + GraphQL features in a regulated, high-frequency release environment; Node.js reporting service.
Technical Lead, React · ByYuto, Miami (remote)
Architecture and delivery across concurrent client projects; built a hybrid team of employees and contractors.
Open source
AI Development Team: a Claude Code plugin where a project-manager agent splits work across backend, frontend, database and QA agents running in parallel in isolated git worktrees.
Work with me
I'm available for senior full-stack or AI-integration work: remote, contract or full-time, invoicing in USD. Certified Scrum Master, Product Owner and Developer; English C1.