Jose Maria S.

Sr. Software Enginner

Senior Software Engineer with 17 years of experience building backend systems at scale — from fintech platforms at PayPal/Braintree and MercadoLibre to AI infrastructure at Upwork. Currently focused on conversational AI and LLM evaluation: I architect the backend for AI-powered chat products, build LLM-as-a-Judge pipelines with Spring Batch, and design the observability layer that makes language model outputs measurable and trustworthy in production. My stack: Java (21/25), Spring Boot, microservices, AWS, PostgreSQL, Redis — with hands-on experience in reactive systems (WebFlux), GraphQL, and distributed architecture. I bring engineering rigor to the AI layer: not just wiring up LLMs, but building the evaluation, resilience, and observability infrastructure that makes them production-ready.