Selected projects
Python · PyTorch · Transformers · PEFT (LoRA) · Colab
SFT, DPO and GRPO written from scratch in PyTorch with Claude Code, then used to study what a 0.5B language model learns when its RL grader has a loophole: one grader also pays the answer the user suggested, the other pays any final line that contains the right number.
- A grader that also pays the answer the user suggested drove copying of wrong suggestions from 7% to 97% of training samples. The habit carried over to unseen phrasings (64%) and to SVAMP problems (62%).
- In 89% of the copies the reasoning itself arrives at the user's number, usually through a false equation, which a consistency monitor cannot see. Penalising what that monitor flags cut flagged copies from 10.8% to 1.8% while copying stayed at 96%.
Repository · Results · How the code works
Postman · Newman · pytest · PostgreSQL · FastAPI · GitHub Actions
A full QA cycle on a sales-commission REST API, the kind of calculation that sales performance management software automates: split credit, clawbacks on returns, a 50% gate, tiered accelerators and a cap.
- 92 risk-based test cases traced to the requirements, and 8 defects found in the first build, 2 of them critical.
- A parallel run against an independent Excel model measured 6,566.74 MXN overpaid by the first build and 750 of 750 payouts correct after the fixes.
Case study · Repository · Newman report
Java · Spring Boot · Flask · Django · PostgreSQL · MongoDB · Docker
A small polyglot platform that ingests request telemetry, reports service-level objectives and detects anomalies: Spring Boot ingestion, a Flask analytics API, a Django back office, PostgreSQL and MongoDB.
- 1.4 million simulated requests over ten days with three injected incidents, all three detected and nothing else.
- A Monte Carlo calibration over 40 runs cut false alarms from 18 to 1 without missing an incident.
Repository
Python · faster-whisper · Claude Code · Anthropic API · ChromaDB · ffmpeg
Turns four-hour class recordings into structured Obsidian notes with no manual steps, then answers questions about past classes citing the class and the minute: local transcription on the CPU, notes written by Claude Code in headless mode and an agent over hybrid retrieval.
- Fits in 8 GB of RAM: silence-aligned ten-minute chunks cut peak audio memory from more than 6 GB to about 0.7 GB on a two-hour recording.
- Hybrid retrieval over notes and transcripts, with multilingual embeddings and Spanish BM25 merged by Reciprocal Rank Fusion. The agent answers only with real citations or says the notes do not cover it.
Repository
Python · pandas · SQL · Star schema · Chart.js · Statistics
Diagnosis of a department-store delivery network, from 62,420 raw shipment records to an executive dashboard. The monthly report said 95.7% of deliveries were on time and in full, yet management felt deliveries were getting slower. The analysis shows where and why.
- Cleaning with lineage: 62,420 raw records reduced to 59,615 shipments, with every exclusion logged.
- Stores compared with their own zone through Wilson intervals, so only 1 of 61 stores is flagged as significantly worse.
Repository · Open the live dashboard
Python · pandas · Excel · pytest · Bitso and Binance APIs
Moving averages, MACD(12, 26, 9) and RSI implemented from first principles for a finance diploma, then extended into a batch run over 35 equities listed on the Mexican Stock Exchange and a bitcoin cost comparison across Mexican platforms.
- Cross-validated against a 3,815-formula Excel model to within 5 × 10⁻¹³, recalculated in CI on every push.
- Bitcoin with pesos: live Bitso and Binance order books against Mercado Pago, measured from the prices its app shows. Buying and selling at once costs 0.27% on Binance and 3.98% on Mercado Pago.
Repository
Small language model from scratch
Python · PyTorch · NumPy
Every component of a small language model, implemented and then trained, for Carnegie Mellon University's Introduction to Modern AI (online, January to April 2026).
- An autodiff engine, a BPE tokenizer and the Adam optimiser written from first principles.
- A decoder-only transformer with masked multi-head attention, a KV cache, RMSNorm and a gated MLP, trained on TinyStories.
The code stays private under the course's academic integrity policy. Its post-training part is rebuilt in the open in the reward-hacking project.
Python · pandas · astropy · scikit-learn · TOPCAT
Spatial and kinematic characterisation of the Milky Way's stellar populations, built by cross-matching Gaia DR3 astrometry with APOGEE-2 DR17 spectroscopy.
- 682,284 sources reduced to 281,612 stars through documented cuts on signal-to-noise, astrometric fit, radial-velocity scatter and parallax.
- Velocity ellipsoid tilted by a vertex deviation of about −26.6°, consistent with asymmetric drift.
Repository · Report (PDF)
Python · TensorFlow / Keras · scikit-learn · Transfer learning
Binary classification of 5,608 MaNGA galaxy images into early types and late types, from a baseline CNN to transfer learning, with the class imbalance handled explicitly.
- Baseline CNN: 81.0% test accuracy, held back by a recall of only 0.68 on late types.
- A deeper CNN reached 86.3% test accuracy and raised late-type recall to 0.77.
Repository
More projects, grouped by area, in the Professional Log.
Experience
AI Trainer, Software Validation & NLP2026
DataAnnotation · Remote
Tested unreleased LLMs across 10+ projects with adversarial prompts that exposed logic failures and policy violations, reporting each one in expected-versus-actual form. Designed the rubrics and metrics used to score model outputs, and provided RLHF feedback and NLP annotations for model evaluation and fine-tuning.
Language Specialist and Freelance AI Trainer2026
Meridial Marketplace · Remote
Reviewed and corrected LLM outputs in multilingual human-in-the-loop pipelines, giving structured feedback used to guide training.
Freelance Field Data Verification Specialist2026
Independent contract · Mexico City
Collected and verified data on commercial venues through site visits and digital documentation, keeping the dataset accurate and complete.
Freelance Web Developer2025
Ashland Chemical de México · Mexico City
Built an interactive product-presentation website for private-school outreach, from client requirements to a deployed interface.
Research Assistant2024
UNAM, with Dr Gabriella Piccinelli Bocchi and Dr Ángel Sánchez Cecilio · Mexico City
Reviewed the cosmology literature, wrote a literature review on cosmological perturbations and presented the theory to the research group every week.
Science Communicator (volunteer)
Institute of Physics, UNAM · Mexico City
Presented cosmology research to audiences ranging from children to researchers in other fields, and built a live-camera demo that simulates a gravitational wave passing through the viewer.