Staff Machine Learning Engineer (Infrastructure)

About Nu

Nu is the world’s largest digital banking platform outside of Asia, serving over 105 million customers across Brazil, Mexico, and Colombia. The company has been leading an industry transformation by leveraging data and proprietary technology to develop innovative products and services. Guided by its mission to fight complexity and empower people, Nu caters to customers’ complete financial journey, promoting financial access and advancement with responsible lending and transparency. The company is powered by an efficient and scalable business model that combines low cost to serve with growing returns. Nu’s impact has been recognized in multiple awards, including Time 100 Companies, Fast Company’s Most Innovative Companies, and Forbes World’s Best Banks. Learn more: https://international.nubank.com.br/careers/

About the role

At Nubank, one of our engineering principles is "Leverage Through Platforms". We believe that platforms are a very efficient way of solving complex concerns that are needed for different products and teams.

The AI Infrastructure Squad within the AI Core BU builds and scales the foundational cloud, data, and AI infrastructure that powers machine learning workloads across the organization. We design and optimize high-performance training, inference, and data processing systems while ensuring reliability, scalability, and efficiency. Our team enables AI practitioners by providing robust compute, model serving, monitoring, and orchestration frameworks to drive innovation and operational excellence.

As a Software Engineer in the AI Core BU, we expect you to demonstrate:

• Strong expertise in cloud infrastructure (AWS or GCP) and distributed computing.
• Experience with Kubernetes, container orchestration, and infrastructure as code (Terraform, Pulumi).
• Proficiency in programming languages. Experience with Python and Go is a plus.
• Experience writing ETL pipelines (experience with Spark or BigQuery is preferred)
• Experience with ML infrastructure, including model training, batch and online inference, and monitoring.
• Strong knowledge of networking, storage, and security in large-scale systems.
• Familiarity with workflow orchestration tools (e.g., Dagster, Airflow) and model-serving frameworks (e.g., Ray Serve, vLLM).
• Experience optimizing performance and cost efficiency of AI workloads on cloud and on-prem environments.

Project Experience:

• Proven track record of leading complex infrastructure projects from design to production.
• Comfortable working on ambiguous and evolving projects, quickly identifying key challenges and driving solutions.
• Experience in designing high-availability, fault-tolerant systems for AI/ML workloads.
• Has worked on developer tooling, platform engineering, or ML infrastructure, ensuring AI teams can build and deploy efficiently.
• Hands-on experience with monitoring, observability, and alerting for production systems.
  
  

We’re looking for individuals who thrive in horizontal, high-impact teams that build foundational infrastructure for multiple AI initiatives. People who enjoy solving deep technical challenges at the intersection of AI, cloud, and distributed systems, and who take ownership with a strong product mindset - ensuring infrastructure is reliable, scalable, and built around user needs. We value collaborators and mentors who help teammates grow while upholding high engineering standards. If you’re passionate about building scalable, efficient, and cost-effective AI infrastructure that drives meaningful, real-world impact, we’d love to meet you.

If you feel interested in these challenges and want to work on a very engaged and talented team, this is the place for you!

What we have to offer

• High-Impact, Cross-Functional Work – Our team sits at the core of AI operations, enabling ML engineers, researchers, and data scientists to build and deploy models at scale. You'll work across multiple teams and business units, directly shaping AI-driven products and decisions.
• Cutting-Edge AI & Cloud Infrastructure – Be part of a team that designs and operates high-performance AI infrastructure, spanning cloud, data, and ML platforms. You'll tackle technical challenges in distributed systems, model serving, and large-scale data processing.
• 0 to 1 & Large-Scale Initiatives – Work on both greenfield projects and mission-critical AI infrastructure, from building scalable training pipelines to optimizing real-time inference workloads. Your work will directly influence the efficiency and scalability of AI across the company.
• Growth & Ownership Opportunities – As a senior engineer, you'll have the autonomy to drive technical direction, lead high-impact projects, and contribute to architectural decisions. You'll also have opportunities to mentor others, shape engineering best practices, and grow into a leadership role.
• Culture of Excellence & Collaboration – Join a team that values deep technical expertise, curiosity, and a strong engineering culture. We operate in a fast-moving environment where innovation, reliability, and efficiency drive everything we build.

Our Benefits

• Remote work, with quarterly trips to Sao Paulo to build relationships with coworkers. 
• Top Tier Medical Insurance
• Top Tier Dental and Vision Insurance
• 20 days time off, 14 company holidays, and great culture that emphasizes work life balance. 
• Life Insurance and AD&D
• Extended maternity and paternity leaves 
• Nucleo - Our learning platform of courses
• NuLanguage - Our language learning program
• NuCare - Our mental health and wellness assistance program
• Extended maternity and paternity leaves 
• 401K
• Saving Plans - Health Saving Account and Flexible Spending Account