Freelancer profile translated to English.
Back to original languageAbout Guillermo
ML & Systems Engineer with 5+ years of experience in production data platforms and 3+ years designing systems with LLMs in real-world environments.
Founder of Hyperborea Technologies. I work end-to-end: architecture, data, ML, and deployment. Solid experience in fintech (multi-custodian wealth management platforms, performance calculation, financial reconciliation) and in critical high-reliability systems.
Specialized in:
RAG systems and LLM applications in production (LangChain, MCP)
Data Engineering: ETL pipelines, time series, PostgreSQL/Supabase
Event-driven automation (n8n, REST, SFTP)
Infra: Docker, Kubernetes, Azure, CI/CD
C2 in Spanish, English, and Catalan. Available for remote projects.
Spanish
Native or bilingual
English
Native or bilingual
Catalan
Native or bilingual
French
Conversational
Remote only
Primarily works remotely
Experience
- Hyperborea TechnologiesFounder & Lead Software EngineerJanuary 2023 - Today (3 years and 7 months)◖ Sole architect and engineer of a financial operations platform for an international airline — greenfield design covering event-driven automation, multi-source data consolidation, REST + SFTP integrations, and executive reporting dashboards.◖ Designed and maintains the full infrastructure stack: containerized services on Azure (Containers + Blob), PostgreSQL data layer on Supabase, CI/CD via GitHub Actions and Render.◖ Built fault-tolerant n8n orchestration layer with full auditability, dead-letter handling, and scheduled + webhook-triggered pipelines.◖ Performs time-series feature engineering and analytical modelling on operational and financial data to power automation logic and business decision signals.
- Valencia MarML Automation EngineerJuly 2023 - Today (3 years and 1 month)Valencia, Spain◖ Designed and shipped a production multilingual LLM chatbot (LangChain + GPT) on Telegram — reduced client response time by 70% through systematic prompt engineering and data-driven evaluation loops.◖ Built and deployed n8n automation workflows replacing manual reporting, invoicing, and client communication processes end-to-end.◖ Containerized and released AI services via Docker with CI/CD pipelines; authored onboarding documentation and trained non-technical staff on AI workflows.
- Appen / Data AnnotationSenior AI & Coding ReviewerMay 2023 - Today (3 years and 3 months)United States◖ Evaluated and fine-tuned LLM outputs across coding, mathematics, and multilingual tasks (EN / ES / CA / FR) under rigorous AI safety and rubric-based QA protocols.◖ Developed prompt engineering strategies that measurably improved model robustness and reduced systematic failure modes across evaluated models.◖ Contributed structured error analysis to RAG and LLM application design, surfacing recurring retrieval and generation failure patterns to research teams.
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Education
- MScUniv. Colorado Boulder2026MSc
- BScCatholic Univ. Valencia2019BSc