Ruan
From Brazil (UTC-3)
Ruan – LLM, Python, RAG
Ruan is a Senior AI Engineer and Agent Architect with ~5 years of industry experience and unusually deep pre-GenAI NLP research roots — including an MSc in AI (Language Technologies) at the University of the Basque Country and University of Malta, 3 international shared task wins, and a published BM25 retrieval paper. He covers the full AI engineering stack: multi-agent systems in LangGraph, RAG pipelines, LLM-based document processing, vector search, and production fine-tuning on GPU clusters. He has shipped across fintech, government document processing, and open-source NLP tooling, and consistently ties architectural decisions to measurable business outcomes.
6 years of commercial experience in
Main technologies
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Let’s get started today!Experience Highlights
AI Engineer
Three Azure-based commercial AI pilots for a large enterprise software client: automated document-type classification, OCR/LLM extraction, and stakeholder-facing review tooling. Covered a workflow processing 1M+ annual applications, from evaluation setup through production deployment and engineering handoff.
- Automated document-type screening with Azure Document Intelligence and LangChain, producing structured outputs with 95%+ accuracy.
- Course-corrected an underperforming OCR/LLM extraction pilot by building evaluation benchmarks and identifying Azure AI Foundry alternatives capable of 90%+ field-level accuracy.
- Built React-based reviewer tools, converted 40+ field corrections into prompt updates, deployed to Azure VM environments, and mentored 2 SWEs through 10+ knowledge-transfer sessions.
AI Engineer
Product and technical delivery for a 6-month RAG proof of concept at a fintech platform processing 20% of all invoices issued in Brazil.
- Accelerated Weaviate vector indexing by 99%+ by replacing full-corpus retrieval with partitioned searches, discovered through BigQuery invoice data analysis.
- Optimized retrieval and ranking to 90%+ recall while cutting candidate depth from top-100 to top-20 — surfacing relevant matches with 80% fewer candidates.
- Interviewed 10+ candidates and mentored 1 SWE to enable the transition from successful PoC to production.
AI Engineer
AI system suite for a Brazilian digital bank serving 30M+ customers, comprising a LangChain/LangGraph GenAI sales agent for card upgrades, a BigQuery-driven lead qualification pipeline, and a RAG-based bank product Q&A system — covering the full lifecycle from lead selection through conversational AI to product information retrieval.
- Developed a GenAI card-upgrade sales agent with LangChain and LangGraph, launching a 300+ user production pilot that cut customer acquisition cost by 6x while matching human-operator conversion rates.
- Used BigQuery analytics and time-series modeling to identify low-friction upgrade leads and feed qualified users into the AI workflow.
- Rescued an underperforming RAG system, beating OpenAI-based accuracy benchmarks and reducing inference costs by 90% through retrieval and prompt engineering improvements.
AI Engineer
AI research and open-source NLP tooling across three organizations (one later acquired by Hugging Face), covering embedding-based annotation workflows, weak supervision, semantic similarity, legal entailment, sentiment analysis, and retrieval systems.
- Built Sentence Transformers + FAISS weak-labeling workflows with Snorkel, raising rule coverage from 32% to 79% and downstream model accuracy to 86%.
- Implemented embedding-based annotation features and contributed 68K+ lines of production-ready open-source code.
- Won 3 international NLP shared tasks in legal entailment, semantic similarity, and aspect-based sentiment analysis, beating runner-up teams by up to 6.4 F1 points.