Javier Villanueva

Senior Backend Engineer · AI Engineering

Senior Backend Engineer with 20 years of experience, the last 4 in travel tech.

I specialize in PHP backends with DDD/CQRS architectures and a high-availability stack: Kafka, ClickHouse, PostgreSQL, Kubernetes.

Co-founder and CTO for 8 years of a digital marketing agency, where I built proprietary attribution and measurement software at scale.

Over the last few months I've pivoted toward agentic AI systems applied to real domain problems: autonomous agents with tool use and evals, and memory and retrieval layers for LLMs (RAG, MCP, context orchestration). I write about it on the blog as I build it.