Now · Founding engineer at a stealth AI startup

I build AI agentsthat do real work.

I’m Felipe Ribeiro: founding engineer at a stealth AI startup, founder of MedAlvo, and an aerospace engineering student at ITA. I like systems where a wrong answer costs real money, so I build them tofail loud, not silent.

2017–20Physics & robotics olympiads
ITAAerospace engineering
2025LinkedIn
2025Credix
2026NG.CASH · MedAlvo
nowFounding engineer
Fig. 1: Trajectory, not to scaleStill climbing ↗
01Selected work

Things I’ve shipped

Products with paying users, open-source tools people install, and the experiments in between.

Founder2026 —

MedAlvo

An adaptive prep platform for Brazilian medical residency exams, run as a self-driving company: AI agents in cloud VMs scrape, OCR, deduplicate and QA the question bank and handle daily operations.

  • FSRS v6 + Thompson Sampling decide what you see next
  • 2PL IRT calibrates difficulty; Bayesian Knowledge Tracing models what you know
  • FastAPI + Postgres/pgvector on Cloud Run, React on the front
163k+official exam questions
2,045full past exams
  • FastAPI
  • Postgres
  • pgvector
  • Cloud Run
  • React
  • AI agents
MedAlvo landing page: “Cada questão mira a sua residência”, with an adaptive study dashboard
Open source2026

penpad

Turns Markdown + LaTeX notes into realistic handwritten pages for iPad, Goodnotes, Notability and reMarkable. A writer model varies every glyph while a legibility clamp keeps it readable.

  • Fractions, integrals, roots and vectors laid out in handwriting
  • Seed-reproducible output, offline, pure pip install, cross-OS CI
  • Python
  • resvg
  • LaTeX
A page of damped-oscillator physics notes rendered in handwriting by penpad
02Experience

Flight log

Remote roles across San Francisco, São Paulo, Belgium and New York, mostly putting LLMs into production.

Sep 2026 — nowStealth AI startupFounding EngineerSan Francisco · remote

Building Milo, a peer-to-peer personal AI for teams. Each employee’s agent runs in its own Linux microVM.

  • Shipped Microsoft Teams and Google Chat integrations at parity with Slack and WhatsApp: act-as-user OAuth, streaming, files and voice transcription.
  • Built the credential layer for the hosted browser agent: an encrypted vault where OTPs and secrets are injected by alias, so they never enter model context.
  • Eval-first shipping: bilingual ship-gate suites replaying production cases, nightly LLM-judged reviews, and an “autopsy” tool that reconstructs any conversation end to end.
Jan 2026 — Sep 2026NG.CASHProduct EngineerSão Paulo · remote

Production LLM agents and full-stack systems for a Brazilian fintech, where a wrong answer costs real money.

  • WhatsApp debt-negotiation agent with multi-model orchestration and pricing kept deterministic in code: 19% lower latency, 0 leaks across a 34-attack prompt-injection battery.
  • Re-platformed legacy payroll into Fastify + React on Cloud Run with Terraform, plus a Gemini pipeline that validates contractor invoices.
  • Automated Legal’s judicial-notification triage with multimodal OCR and entity extraction, removing ~95% of manual review.
Jul 2025 — Jan 2026CredixML Engineer, Credit & RiskBelgium · remote

Credit models for emerging-market B2B buyers that drove automated decisions and seller pricing.

  • XGBoost and logistic-regression classifiers that bucket buyers by predicted DPD and loss, deployed to production.
  • SQL + Python pipelines for near-real-time decisioning, with anomaly detection flagging fraud.
Feb 2025 — Jul 2025LinkedInSales Strategy Intern, Data & AINew York · remote

An LLM chatbot over Salesforce CRM data that replaced analyst-mediated forecasts for US & Canada sales.

03Honors & education

Before all this

Years of physics, math and robotics olympiads, 2017 to 2020. That’s where I learned to like hard problems.

International1stOverall, top goldIberoamerican Physics Olympiad
InternationalSilverMedalNordic-Baltic Physics Olympiad
National3×GoldBrazilian Physics Olympiad (OBF)
National2×GoldBrazilian Robotics Olympiad (OBR)
National1×GoldBrazilian Math Olympiad (OBMEP)
Education

Instituto Tecnológico de Aeronáutica (ITA)

Aerospace Engineering, Data Science minor

Expected Dec 2027
04How I work

AI-native, by default

Most of my code is written with a fleet of agents: Claude Code and Codex running in parallel git worktrees, on a remote box, inside tmux. I spend my time on specs, review and evals.

I ship eval-first. If a change touches a model, it doesn’t merge until it passes suites built from real production cases. Anything that has to be exact, like prices, money and credentials, stays in deterministic code and out of the model’s hands.

~ tmux attach -t fleet
  agent-1  feat/streaming     ✓ evals passing
  agent-2  fix/retry-backoff  ✓ evals passing
  agent-3  chore/qa-batch     running…

Illustrative. The agent box sits behind a Cloudflare tunnel on this same domain.

AI & agents
  • LLM agents
  • Multi-agent orchestration
  • Tool use & MCP
  • RAG
  • Evals & guardrails
  • PyTorch
Product
  • TypeScript
  • Node
  • Next.js
  • React
  • Fastify
  • FastAPI
  • Python
Data
  • Postgres
  • pgvector
  • Snowflake
  • DynamoDB
  • XGBoost
  • SQL
Infra
  • GCP Cloud Run
  • AWS
  • Terraform
  • Docker
  • GitHub Actions
  • Linux

Let’s build something
that holds up.