João Barbosa

Wiring bits to bring people together.

HereElsewhere
JuliaMikeEmiPietro CoppolaMychel

5 seeds planted. Plant yours

Work.

Vento

Founding Product Engineer, 2026—

Voice agents that negotiate overdue debt in Brazil, a market that recovers 1-2% of what it is owed.

Interviewed 10+ owners in New York, San Francisco, Manila and Brazil to set product direction.

Ran customer discovery (Mom Test) on 8 theses, backing the pivot into a $9B unrecovered market.

Vento raised a $3M seed round.

Turned discovery with banks and Brazil’s largest collection agency into a 28K-account pilot.

Built the voice agent’s outbound core: STT, LLM and TTS in under 900 ms a turn.

XP Securities

Quantitative Developer Intern, Jul–Aug 2026

Developed the Issuer Opportunity Screener for a credit desk in New York with a 9-figure annual P&L.

Shipped to daily desk production on Bloomberg BQuant (pandas, scikit-learn, SciPy, BQL).

Ranked 275 bond and CDS issuers on 21 features in ~2 seconds, down from ~30 minutes each.

Modeled fair spread by a 5-factor cross-sectional regression and k-means peer groups.

Jane Street

FOCUS Program, May 2026

Selected for the invitation-only week for first-years: trading, low-latency systems, finance and SWE bootcamps.

iFood

Software Engineer Intern → Junior Engineer, 2024–26

Owned the Order External Audit API, opening 15M+ daily log records to integrators.

Queried 6K+ times monthly; cut integrator support requests by 18%, at NPS 96.

Maintained Kotlin and Go microservices in the Order Platform, 4M orders and 600M+ requests a day.

Held 99.99% webhook and MQTT event delivery for 55M+ monthly users and 400K+ restaurants.

Migrated the polling read path from Postgres to Apache Ignite: sub-20 ms at ~1M requests a minute.

Worked the rollback on a 3-hour outage, one of the platform’s worst, after my change met one in flight.

For a lunch rush hour, nobody in Brazil could order McDonald’s. Still tell the story.

RME

Technical Lead, Rede Mulher Empreendedora, 2026—

Leading engineering on a platform pairing 900k+ women entrepreneurs with 200+ mentors.

Replaced per-pair LLM calls with embedding filter and rank: sub-second matching, 6× cheaper.

Open Source

Open-Source Contributor, Google AlloyDB

Building adbo, a command-line client for AlloyDB, Google Cloud’s managed PostgreSQL service.

Directly mentored by Google engineers throughout.

Hackathons

Autonomous Idea-to-Deployment Agent Swarm, Stanford TreeHacks, Feb 2026

Parallel agent harness with state verification to deploy solutions from PRDs autonomously.

Research

Adaptive Demographic Modeling for Public Health Crisis Management, 2023–24

Simulated COVID-19 across 1.2M agents within 5% of the city’s 3-year death toll in 2.5 minutes.

Honors thesis. 4th at Brazil’s largest STEM fair; sought after by two cities in São Paulo state for crisis response.

Particles on Canvas: Creating Digital Art to Further Scientific Divulgation, 2024

First place in Latin America of ~500 teams in a CERN particle accelerator competition.

Led 6 people building a feedforward neural network pipeline from collision data to digital art.

School

B.S. in Computer Science, Carnegie Mellon University, 2025–29

Behring Scholar.

Coursework: Theoretical Computer Science, Functional Programming, Linear Algebra.

Activities: Philantropy Chair, Soccer Intramurals Captain, Residential Assistant.

Tech Fellow, Fundação Estudar, 2025—

60 of ~8,000 applicants.

Estudar Foundation awards fellowships for Brazilian students to study in top universities with the mission of accelerating Brazil's technological development.

Finalist, Brazilian Olympiad in Informatics, 2023

Gold and Silver medalist, Brazil’s Robotics, Science and Astronomy Olympiads, 2022–23

Research Fellow, Universidade Estadual de Campinas, 2022–23

Researched embedded systems for bioinformatics, then cheminformatics for education.

Presented at local, national and international conferences, including the Brazilian and Latin American Congress of Marine Sciences.

Teaching Assistant, Informatics & Systems Development, Technical High School of Campinas, 2022–23

12 hours a week of recitations and 1:1 tutoring for 370+ students across all technical courses.

The full resume