_{llms.txt: an index of my work for language models · CV: English (PDF), 日本語・簡易版 (PDF)}

And what is good, Phaedrus,
And what is not good—
Need we ask anyone to tell us these things?

_{Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance (1974), the epigraph on its opening page}

think

write

read

have fun

Staff Software Engineer & FDE 31yo

Piabrota AI Studio (self-employed, since October 2026)

• wave.piabrota.art: Science, >2k views on Zenodo, fresh on aiXiv
• room.piabrota.art: a 3D room - three.js, 3d model, ambience. idea
• metrics.piabrota.art: homelab numbers - vcpu / ram
• grid.piabrota.art: unstructured grids of the Brazilian coast - wind/temp now, swell later
• skills.piabrota.art: my skill collection - DYOR
• pirsig.piabrota.art: a second brain - obsidian-like
• proof.piabrota.art: Lean 4, Z3 and other formal verification tools -- agda soon
• hermes.piabrota.art: Hermes Agent on NixOS
• rig.piabrota.art: OpenRig fabric on NixOS
• Partnerships or white-label requests: whitelabel [at] piabrota.art

Technical skills and background

• Software development: 10+ years. Mostly Scala for backend and data; Python for ML and Airflow.
• 2015: LIOC, ocean instrumentation lab. FPGA signal processing in LabVIEW (low code) for Brazilian Navy underwater communication
• 2016: Real-time GPS boat tracking over 2G, with mobile phone chips
• 2017: StoneCo, during its IPO. Churn prediction with XGBoost, to replace Bayesian networks
• 2018: a model that recommends a mobile carrier from ping history. Flink - during alpha stage - detects events; Python scores
• 2019: a pre-seed startup. We made an instant transfer between banks. It launched in August 2020, before Pix. A company bought us; then Pix made the product unnecessary
• [UK] 2020: an early startup based in London, in overseas banking. I worked mainly on the Scala backend and the FX APIs
• [US] 2021: a California startup. Semantix bought it
• [US] 2022: promoted to Lead MLOps, consulting for Americanas (B2W, Brazil). ML environments with Kubernetes and Kubeflow
• [US] 2023 to 2024: fraud prevention on Databricks. L5 engineer and Subject Matter Expert of a loss forecasting product. I reported to the CFO. "Values VIP: Tenacious" award, February 2024
• [UK] 2025: TV audience forecasts for 4 channels, indirect contract. AWS: SageMaker, MWAA, S3, Lambda and Step Functions
• [UK] 2026: I redesigned, with DS Lead, all 34 long-term models (2 channels × 17 demographics) as heuristic rules. I took them to production on AWS (SageMaker, MLflow). I resigned on early September 2026

Research: UFSC, until mid-2027

• A team of 5
• h0ffmann/ww3-gpu