I turn manual financial reporting into automated, governed, multi-billion-row lakehouse pipelines —
and ship open-source data platforms on the side.
class LeonardoChalhoub:
role = "AI Data Engineering Tech Lead"
company = "NTT DATA → Bradesco (mission-critical financial reporting)"
based_in = "Brazil · remote-first"
experience = "15+ years · Finance → Data Science → Production Data Engineering"
leads = "an 8-engineer team in a regulated banking environment"
builds_with = ["Databricks", "PySpark", "Delta Lake", "Unity Catalog", "Azure"]
speaks = ["Português (native)", "English (TOEFL 96/120)", "Español (11 yrs)"]
also = "author of *Papéis* (2026) · peer-reviewed finance researcher"
philosophy = "Open. Auditable. Reproducible. FinOps-disciplined."- 🏦 Leading the transition from manual financial reporting → fully automated batch algorithms in Databricks, on a Medallion architecture (Bronze → Silver → Gold) with SCD Type 1 & 2 and date-based incremental loading over multi-billion-row tables.
- 🎓 MSc in Finance (UFRGS) — published in Brazilian Review of Finance · 30+ industry certifications.
- 🌎 Career spanning Itaipu Binacional, a finance professorship, the Ciudad del Este tri-border trade hub, and Big-Data teams at Unilever, AB-InBev, GSK, and CPFL.
- 🛠️ I ship production-grade open-source platforms — civic-data lakehouses, financial dashboards, and AI-native SaaS — with strict FinOps discipline (one of them runs on a lifetime cost of US$70).
Open-source, free, and auditable — civic data, applied finance, and AI-native SaaS.
| Project | What it is | Stack |
|---|---|---|
| Mirante dos Dados | Production-grade open lakehouse for Brazilian public microdata (CGU, DATASUS, IBGE, BCB, MTE). Medallion over Delta Lake → versioned JSON → React platform + peer-reviewed LaTeX Working Papers compiled in CI. 7 papers · 13 tests · lifetime cost US$70. | Spark Delta Lake Asset Bundles React LaTeX Actions |
| Applied Finance | Open lakehouse + dashboard for the B3 stock market — ~400 tickers × ~26 years via a Python port of yfR, Bronze→Silver→Gold on Delta. Per-ticker KPIs, sector & correlation maps, IBOV overview. Phase 2: CVM fundamentals + in-browser Markowitz. No DB, no server, no login. |
Databricks Delta Lake Next.js 16 Python 3.11+ |
| Project | What it is | Stack |
|---|---|---|
| Foco Contábil | Multi-tenant SaaS taking a Brazilian accounting firm from CNPJ registration → signed DRE. Per-workspace Postgres RLS on every table, dimensional accounting reports (Balancete / Balanço / DRE), Asaas Pix+Boleto, NFS-e queue, A1 cert vault, immutable audit log, RBAC. | Next.js 16 Supabase RLS Vercel |
| Caixa Forte | Open-source personal finance for Brazilians — add transactions by tap, type, or voice note (Whisper transcription + Llama 3.3 structured extraction). Budgets, recurring, charts, CSV import. Council-reviewed 9.2/10. R$ 0 forever. | Next.js 16 Supabase Groq Whisper |
| Amazing School | "The teacher is the star. The AI is the stage crew." A teacher-first OS for autonomous English teachers — lesson planning, homework review, Whisper pronunciation tracking, billing, class management. AI drafts; the human owns the student. | Next.js 16 Supabase Groq Whisper |
| PetZap | Full-stack SaaS for pet health, spending & vaccine schedules — added by tap, text, or voice via Telegram bot (Gemini multi-modal parsing). Reminders, dashboards, history. CI green, i18n, RLS. | Next.js 16 Supabase Gemini Telegram |
| Clube da Matemática | Accessibility-first open high-school math curriculum — 120 lessons, ~4,770 sourced exercises (book·page·license — nothing hallucinated), 1,800 exam questions, 11 UI languages, Web Speech "Listen" on every lesson. | Next.js 16 MDX KaTeX GitHub Pages |
MSc in Finance (UFRGS) · 30+ certifications total · Trilingual (PT native · EN TOEFL 96/120 · ES 11 yrs) 📄 Cash Sources and Financial Constraints — Brazilian Review of Finance, 2015 · 📖 Papéis — dystopian novel, 2026
