Build and operate production machine learning systems for dispute optimisation, owning model training, deployment, monitoring, feature pipelines, and backend integrations across the Disputes platform.
Senior Machine Learning Engineer
📜 Description
- Build forecasting models and models that assess and guide marketing investments.
- Frame ambiguous business problems as well-defined modeling problems and align stakeholders.
- Design, train, validate, and tune models with statistical rigor and business relevance.
- Engineer and maintain features and datasets for model training and inference.
- Deploy and maintain batch and real-time models, integrating them with other systems and monitoring performance.
- Lead modeling projects end to end, from problem framing through delivery, monitoring, and iteration.
🛠️ Requirements
- Strong foundation in statistics, machine learning theory and modeling techniques (e.g. regression, tree-based models, deep learning)
- Programming experience in Python and familiarity with ML libraries (e.g. scikit-learn, PyTorch, TensorFlow, XGBoost)
- Experience training, validating, and tuning models, with solid understanding of overfitting, bias-variance tradeoff and evaluation metrics
- Understanding of the ML model lifecycle, from training and evaluation to deployment and monitoring
- Ability to write efficient SQL queries and work with analytical data environments
- Strong communication skills to collaborate with both technical and business stakeholders
- Passion for building high-quality, production-grade models
- Experience with cloud platforms such as AWS, GCP or Azure
- Familiarity with distributed systems, microservices and asynchronous architectures
- Experience with feature stores, MLOps tooling and experiment tracking (e.g. MLflow, Feast, Airflow)
✨ Benefits
- Chance of earning equity at Nu
- Extended maternity and paternity leaves
- Health and life insurance
- NuCare - Our mental health and wellness assistance program
- Nucleo - Our learning platform of courses
- NuLanguage - Our language learning program
- Vacations of 15 workdays
- Gym partnership
- Work-from-home Allowance
- Parental Consultancy
Full job description
About Nu
Nu serves more than 140 million customers, guided by a mission to fight complexity and empower people. The company has been leading an industry transformation through innovative products and human-centered services.
Proprietary technology and data at scale power Nu’s digital platform, built to promote financial access, advancement, and transparency. Its business model thrives on customer love and lower costs, feeding a flywheel of growth and profitability.
Visit our Institutional Page
Machine Learning Engineer at Nubank
At Nubank, Machine Learning Engineers sit at the core of how we make decisions at scale. We build, train, and deploy models that drive credit, fraud, risk, personalization decisions and a growing set of AI-native experiences for millions of customers every day. We do it with engineering rigor, statistical depth, and a deep focus on impact.
Our MLEs work across the full modeling lifecycle: framing business problems as ML problems, engineering features, training and validating models, and deploying and monitoring them in production. We value small, independent teams that move fast, own their decisions end-to-end, and hold themselves to a high bar for quality and craft.
Increasingly, that work also includes Generative AI and Agentic Engineering. Depending on the problem, our engineers design and build systems that combine models, tools, workflows, evaluation loops, and human oversight to solve real business tasks reliably in production.
We strive for state-of-the-art ML practices that currently include a variety of technologies. While we value candidates that are familiar with them, we are also confident that engineers who are interested in joining Nubank will be able to learn from our team.
Large-scale model training and experimentation pipelines
Feature engineering and feature stores feeding both batch and real-time models
Model deployment and serving in production, with monitoring through operational and business metrics
Distributed data processing for training datasets at scale
Continuous Integration and Deployment into AWS and Kubernetes
Experiment tracking, model versioning, and reproducibility tooling
A robust data platform built on modern ETL/ELT practices
As a Machine Learning Engineer, you’re expected to:
Directly contribute to Nu Colombia’s strategy and performance mainly by building forecasting models and models to assess and decide on marketing investments
Frame ambiguous business problems as well-defined modeling problems
Design, build and validate machine learning models, ensuring statistical rigor and business relevance
Engineer and maintain features and datasets used for training and inference
Deploy and maintain ML models in both batch and real-time scenarios, integrating them with other systems and monitoring through operational and business metrics
Lead modeling projects end-to-end — from problem framing and stakeholder alignment to delivery, monitoring and iteration
Translate business needs into modeling strategies aligned with Nubank's architecture and long-term goals
What We're Looking For
Strong foundation in statistics, machine learning theory and modeling techniques (e.g. regression, tree-based models, deep learning)
Programming experience in Python and familiarity with ML libraries (e.g. scikit-learn, PyTorch, TensorFlow, XGBoost)
Experience training, validating, and tuning models, with solid understanding of overfitting, bias-variance tradeoff and evaluation metrics
Understanding of the ML model lifecycle, from training and evaluation to deployment and monitoring
Ability to write efficient SQL queries and work with analytical data environments
Strong communication skills to collaborate with both technical and business stakeholders
Passion for building high-quality, production-grade models
Nice to Have
Experience with cloud platforms such as AWS, GCP or Azure
Familiarity with distributed systems, microservices and asynchronous architectures
Experience with feature stores, MLOps tooling and experiment tracking (e.g. MLflow, Feast, Airflow)
Knowledge of data architecture patterns (Data Lake, Data Warehouse, Data Mart)
Experience with data visualization tools (Looker, Power BI, Tableau or similar)
Knowledge of software engineering best practices: testing, clean code, documentation
Core Benefits
Chance of earning equity at Nu
Extended maternity and paternity leaves
Health and life insurance
NuCare - Our mental health and wellness assistance program
Nucleo - Our learning platform of courses
NuLanguage - Our language learning program
Vacations of 15 workdays
Gym partnership
Work-from-home Allowance
Parental Consultancy
Relocation Assistance Package, if applicable
Work Model
Hybrid 2-3 times/week: Our hybrid work model brings us to the office at least twice a week, on strategic days designed to maximize team connection and collaboration.
For more details, visit https://building.nubank.com/nu-hybrid-work-model/
Role Location
Bogota, Colombia.
Our recruitment process may involve the use of artificial intelligence–enabled tools, such as automated interview transcription and analysis, to support the evaluation process. Artificial intelligence is not used to make final hiring decisions; all decisions are made by human reviewers.
To maintain a consistent and fair process for every candidate, Nu does not provide individualized technical feedback. See how our policy works here
Similar jobs
Search more Machine Learning Engineer jobsAs a Senior Machine Learning Engineer, you will take ownership of the Dynamic Risk Score product, developing and deploying ML models to enhance financial crime prevention for clients.
Senior Applied ML Engineer | Kimchi (Model Router)
Own the applied ML lifecycle for Kimchi’s model router, from training data and objectives to production-parity evaluation and online iteration, improving task quality, cost, and speed.
Set machine learning direction and deliver production LLM systems, from post-training and agent workflows to evaluation and dialogue improvements that shape user experience, retention, and monetization.
Build and operate recommendation, ranking, and personalization models that shape advertiser campaign performance, while owning production ML systems and the evaluation frameworks used to test and ship them safely.
