Fabricio
From Argentina (UTC-3)
Fabricio – Python, Ruby, Typescript
Fabricio is a senior full-stack engineer with a strong backend and AI focus, specializing in Python, Ruby on Rails, and production-grade GenAI/LLM pipelines. He has demonstrated expertise in building multi-stage LLM systems, optimizing data flows, and delivering robust backend solutions for fintech and advertising platforms. His strengths include applied AI engineering, backend performance, and clear, honest communication. He is best suited for backend or AI engineering roles rather than infrastructure or frontend leadership positions
16 years of commercial experience in
Main technologies
Additional skills
Direct hire
PossibleReady to get matched with vetted developers fast?
Let’s get started today!Experience Highlights
AI/LLM Engineer
An automated content platform that turns thousands of scraped web sources into original published articles with zero human writing. An 8-stage LLM pipeline extracts claims, clusters stories, and writes information-gaining content — meaning articles that add something new instead of repeating what's already published. Each stage runs on the cheapest model that meets its quality bar, cutting cost per article to a fraction of an all-frontier-model setup.

- Built an 8-stage LLM pipeline that turns thousands of scraped web sources into original published articles: ingestion, claim extraction, semantic clustering, editorial synthesis, validation and post-production.
- Designed a hybrid model-routing architecture — self-hosted local models (Ollama on a dedicated GPU node) for extraction and classification, frontier APIs (Claude, DeepSeek) only where judgment and prose quality matter.
- Built a model evaluation harness with a golden-reference set and LLM-as-judge scoring; used it to detect a silently degrading pipeline stage and replace the model on evidence: chose DeepSeek as the cheapest option that matched the quality bar.
- Implemented semantic deduplication and clustering with sentence-transformer embeddings, pgvector and HDBSCAN.
- Made the whole pipeline idempotent and resumable: PostgreSQL as the state layer, unique constraints and upserts per stage, safe to re-run after any crash.
- Built the supporting infrastructure end to end: PostgreSQL/pgvector on Docker, automated daily telemetry via systemd on a Linux node, Telegram monitoring, and a Next.js front end on Vercel.
Senior Software Developer
A white-label client-retention platform for mortgage lenders and loan officers. Borrowers receive monthly branded home value reports built from multiple valuation data providers, and the platform monitors a network of 2,000+ mortgage and real-estate sites to detect when a client starts shopping for a refinance or HELOC, alerting their loan officer in time to save the deal. Serving thousands of active users across multiple lenders. I owned the data layer the product depends on: multi-source ingestion, valuation data flows, and database performance.
- Optimized the PostgreSQL queries behind the value-report generation path--the platform's heaviest workload: 88% runtime and 85% memory reduction, through execution-plan analysis, indexing, and query restructuring.
- Rebuilt the lender data import system — the onboarding path for every new lender joining the white-label platform: turning a fragile, manual-intervention process into a reliable, repeatable one.
- Owned the architecture and stability of the critical financial data flows: multi-source valuation data feeding thousands of monthly client reports.
- Ran code reviews and provided technical mentorship across the team, and helped define engineering processes for the development lifecycle.
- Worked with geospatial property data at scale: PostGIS-backed queries, geographic boundaries, and map-based search (Mapbox).
Senior Software Developer / Consultant
A platform that reimburses fleet drivers for charging company electric vehicles at home. The system ingests vehicle telematics (charging sessions, battery and usage data) from the two leading fleet-telematics providers (Geotab and Samsara), normalizes it into a central data hub, and calculates accurate electricity costs per charging session, so drivers get paid quickly and employers get verifiable numbers.

- Built the ETL pipelines ingesting fleet-telematics data from the Geotab and Samsara APIs: designed, deployed and owned these services end to end.
- Used Python's asyncio throughout the ingestion layer: telematics APIs are I/O-bound and rate-limited, so concurrent async requests cut sync times dramatically compared to a sequential approach.
- Developed the core data API (FastAPI) serving normalized charging and vehicle data to the reimbursement engine, backed by PostgreSQL.
- Operated the services in production on Heroku, then handed ownership over to the client's in-house team at engagement end.
Senior Full-Stack Developer
A mobile advertising platform delivering video ad campaigns for major consumer brands at massive scale, with a core delivery backend processing 800,000 requests per minute. The platform makes real-time decisions on which ad to serve, to whom, and under which campaign rules, where latency and reliability directly impact revenue.
- Optimized and maintained the mission-critical ad-delivery backend processing 800,000 requests per minute, where every millisecond of latency has direct revenue impact.
- Built advanced ad-targeting features, improving delivery precision and large-scale campaign performance.
- Worked under real high-traffic constraints: caching strategies, query performance and defensive design for systems that cannot go down during live campaigns.
Senior Software Developer / Consultant
A US software consultancy serving clients across industries: executive recruiting, sports training, e-commerce, and design. I worked as a senior engineer across multiple long-term engagements, owning projects end-to-end: scoping with the client, architecture, implementation, and delivery. Each engagement meant a different stack and a different business domain, from custom CRMs to desktop applications and systems audits.
- Designed a custom Ruby on Rails CRM for a high-profile executive-recruiting firm in New York.
- Built a Node.js / Electron desktop application for an online sports-training startup.
- Delivered technical consulting and a full systems audit for a leading Los Angeles design company, including complex Shopify integrations.
- Built and maintained Python/FastAPI backend services for multiple clients across multi-month engagements.
Senior Software Developer
A test-preparation platform for the GMAT, serving students worldwide with practice exams, prep courses, and admissions consulting. The core product was a computer-adaptive practice exam engine designed to replicate the real GMAT experience, with question selection and scoring algorithms that adapt to each student's performance and closely match the official exam's behavior.
- Developed and maintained Ruby-based adaptive algorithms simulating the GMAT exam, with question selection and scoring logic closely matching the official test's behavior.
- Owned stability and new feature delivery across a diverse stack, including Ruby on Rails and PHP, for business-critical applications.
- Built hybrid mobile applications, bringing the exam-prep experience to mobile devices.