~/jvelezmagic
Jesús
Vélez Santiago
I design and build AI products. I start with someone stuck on a task and work backwards to whatever model, data or interface gets them unstuck. Based in Mexico.
$ git log --graph↓- engineering
- science
- teaching

$ cat README.md
About
I'm Jesús — online, jvelezmagic. I trained as a genomic scientist, modeling bacteria and decoding single cells, and slowly followed the data into software.
Today I design and build AI products, starting from the problem rather than the model. Along the way I co-built decoupleR, taught data science on Platzi, and reached the finals of a couple of AI hackathons.
The "magic" in my handle is half a joke: I still love the moment a messy pile of data turns into something people can actually use.
- Based
- Mexico · remote
- Languages
- Spanish, English
- Writes
- Python, TypeScript, SQL, R
- Off-hours
- Camping, sunsets, starry nights
$ git log --graph
The story so far
Building AI products today. It started in a genomics lab, with a lot of teaching along the way.
12 commits · 3 branches · 1 merge · since 2020
??????? · git commit -m "your idea here"
The next commit isn't written yet. If you're working on an AI product, or a problem that might become one, it could be ours.
Message me on LinkedIn ↗04 · HEAD → main
Designing AI products
At uDocz I design and build the AI features people study with: flashcards, quizzes and summaries made from their own documents. I still check the numbers like a statistician.
HEAD → mainML Engineer & Python Developer· uDocz
Retrieval-augmented generation over ~1M documents, real-time AI flashcards and quizzes, and the Airflow + dbt pipelines behind them.
git show 2d0e409 ↓close ↑
now2d0e409 · role
commit 2d0e409 (HEAD → main)
Date: Jun 2023 → now
ML Engineer & Python Developer @ uDocz
+ RAG over ~1M documents: LangChain, FastAPI, Postgres, Redis, open-source embeddings
+ real-time AI flashcards and quizzes generated from each document
+ summaries tuned for SEO and for readers
+ Airflow + dbt pipelines with observability
uDocz ↗Python · FastAPI · LangChain · Postgres · Redis
Advanced document handling & retrieval with LangChain· Course
Hands-on course (in Spanish) on chunking, retrieval and RAG techniques.
Oct 2023291f589 · course
03 · git merge science
From the lab to products
I branched into industry — analytics at Platzi, then automating infrastructure as an ML engineer at Wannabe. decoupleR got published, and the science branch merged into main. It never really left.
Exploratory data analysis· Platzi
Sep 2022d310945 · course
Machine Learning Engineer· Wannabe
Deployment from fully manual to fully automated (GitHub Actions, Docker, Kubernetes); infra cost down 75%, API errors down 90%.
git show 247db42 ↓close ↑
Sep 2022247db42 · role
commit 247db42
Date: Sep 2022
Machine Learning Engineer @ Wannabe
- manual deploys
+ fully automated CI/CD: GitHub Actions, Docker, Kubernetes
+ infra cost -75%
+ GraphQL APIs (NestJS, Apollo tracing), error rate -90%
TypeScript · NestJS · GraphQL · Kubernetes
Merge branch 'science' into main
From research labs to building products — the science never left.
Mar 202269597fd · merge
Data Analyst· Platzi
KPI dashboards in Metabase & Superset and new course-evaluation metrics; halved data extraction time.
git show bde0243 ↓close ↑
Jan 2022bde0243 · role
commit bde0243
Date: Jan 2022
Data Analyst @ Platzi
- decisions based on assumptions
+ KPI dashboards in Metabase and Superset
+ new course-evaluation metrics across Redshift, Postgres, Tinybird
+ data extraction time -50%
SQL · Redshift · Metabase
02 · git checkout -b teaching
Learning out loud
I started teaching what I was learning: a live class on pandas, a talk on packaging code, and my first Platzi courses. Meanwhile the science kept going, automating single-cell pipelines at La Jolla Institute.
Bioinformatics Specialist· La Jolla Institute for Immunology
Automated single-cell pipelines and reports so researchers could explore their own data.
git show 0f9d184 ↓close ↑
Oct 20210f9d184 · role
commit 0f9d184
Date: Oct 2021
Bioinformatics Specialist @ La Jolla Institute for Immunology
- manual cleaning and normalization
+ automated single-cell pipelines and experiment reports
+ tested, documented internal libraries
R · Python · single-cell
Start creating packages to share your code· Saez Lab
Jun 20214f4a652 · talk
Environments for data science — Jupyter, Conda & beyond· Platzi
Two courses on setting up productive, reproducible data science workbenches.
May 2021aec4e15 · course
Pandas and its ecosystem· Platzi Live
Apr 2021b742896 · talk
01 · git init
Code as a lab instrument
It started in genomics. At Heidelberg's Saez Lab I spent a year building decoupleR, an R package to infer biological activity from omics data — and found I liked building the instrument as much as using it.
R Software Developer· Heidelberg University · Saez Lab
Co-built decoupleR — 10+ statistical methods in one framework; Bioconductor acceptance went from ~3 months to 2 weeks.
git show 7df2b0a ↓close ↑
Aug 20207df2b0a · role
commit 7df2b0a
Date: Aug 2020
R Software Developer @ Heidelberg University · Saez Lab
+ 10+ statistical methods in one framework (decoupleR)
+ test-driven, cross-platform R package
- ~3 months to Bioconductor acceptance
+ 2 weeks to Bioconductor acceptance
Bioconductor ↗R · Bioconductor
$ gh repo list --pinned
Side projects
Things I built outside the day job: open source, hackathon finals and research.
saezlab/decoupleR
open sourceInfer biological activities from omics data with an ensemble of statistical methods. Co-built at the Saez Lab; on Bioconductor.
R3132021
cookiecutter-conda-data-science
open sourceAn opinionated project template for data science with Conda and Jupyter.
Python892021
pandas-missing
open sourceA pandas extension to explore and handle missing values.
Python12022
platzi-reviews-server
open sourceGraphQL server over 1M+ scraped course reviews.
TypeScript2023
Flow Genius
★ FinalistNo-code builder for conversational bots. AI21 Labs Hackathon.
Python32023
CareConnect
hackathonCare assistant that teaches teens with type 1 diabetes about their condition, grounded in doctors' documentation.
2023
Cultivate
★ FinalistAI interviewer that screens candidates for culture fit. ChatGPT & Whisper API Hackathon.
TypeScript2023
Bacterial filamentation
researchModeling how growing long — instead of dividing — helps bacteria survive toxic environments.
2021
Biomaths in times of coronavirus
researchODE models searching for an optimal lockdown span for Mexico City.
12020