Experience | Luiz Fernando

Data Scientist III

CloudWalk

01/2026 - Present

CloudWalk is a Brazilian unicorn democratizing the payment market with state-of-the-art technology through InfinitePay. As part of the credit team, I'm responsible for the creation, deployment, and maintenance of credit models, as well as monitoring and analyzing all data related to credit operations.

I co-created a model registry, serving, and inference platform that scaled the credit team's loan decisioning infrastructure from 1 to 20+ models — including GPU-accelerated pipelines and online inference for credit card products — scoring more than 7M users.

Currently, I'm building the next generation of financial models: a tokenizer for financial events (implemented in Rust), pre-training and fine-tuning transformer-based models on GPU clusters.

LLM Training Rust Tokenization MLOps Credit Modeling GCP

Nubank

Machine Learning Engineer

09/2022 - 12/2025

The largest digital bank outside Asia, serving 100M+ customers. Four roles across the Credit and Platform teams:

ML Engineer — Platform Team

09/2025 - 12/2025

Spearheaded a centralized Feature Store standardizing feature discovery and versioning for 30+ teams. Architected data immutability systems with Delta Lake, built low-latency APIs for global feature discovery, and developed an MCP to help agents interact with the Feature Store.

ML Engineer — Credit Team

09/2024 - 09/2025

Engineered a Python model orchestration library (batch/real-time), cutting average deployment time by 60%. Led the migration of monitoring services to a Spark/Scala framework (5h to <1h contribution lead time) and deployed a flexible binning framework (3 months to 2 weeks change cycles). Mentored two junior engineers.

Junior ML Engineer

12/2023 - 09/2024

Refactored, retrained, and redeployed major versions of Nubank's primary risk and spend model, improving performance by nearly 2 percentage points. Developed architectural tests for a new population, impacting 500k+ potential clients.

ML Engineering Intern

09/2022 - 12/2023

Migrated the Curves framework to a modern stack, boosting Business Analytics productivity. Integrated two new data providers into the primary credit risk pipeline (batch and online) and retrained key model versions.

Machine Learning Feature Store Spark Scala Model Deployment

Machine Learning Engineer (Research Project)

Huawei / Embrapii — Solar Tracking Control (AI Based)

02/2022 - 08/2022

Deployed Random Forest models on a 50,000-point solar characterization dataset, increasing the plant's energy generation efficiency by up to 12%.

Built a feature serving system using Airflow and InfluxDB to process IoT sensor data with sub-500ms latency, enabling real-time analysis for energy optimization.

Data Science NoSQL Renewable Energy

Data Engineer (Research Project)

MGI Tech

08/2021 - 08/2022

Built robust ETL pipelines from transactional SQL databases to business dashboards, significantly improving the company's analytical capabilities and data-driven decision making processes.

ETL Pipelines SQL Data Engineering

Cloud AI Training PB

Huawei / Embrapii

03/2021 - 07/2021

Monitored and developed research activities within the Artificial Intelligence Training scope (HCIA AI 3.0 Certification). Created tooling to facilitate the students' routine.

AI Training Research

Professional Experience