Principal Engineer - Library Architect

Nubank; Palo Alto (CA); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Medical Insurance

Dental & Vision Insurance

401(k) matching

Generous time off

Job summary

Nubank is seeking a Library Architect to take ownership of the core programming language ecosystem and shared abstractions that power our backend microservices. You will oversee, govern, and elevate Nubank's foundational infrastructure libraries, ensuring they are stable, idiomatic, and maintained to the highest standards across multiple languages.

You will define the Nubank Way for building resilient core software libraries, interacting across the bank's language landscape, and ensuring

Qualifications

• Experience building high-throughput backend ecosystems at scale.
• Experience standardizing libraries across large distributed systems.
• Strong knowledge of polyglot runtimes and language interoperability.
• Commitment to high-integrity, forward-compatible design.
• Ability to partner with senior leadership to drive standards across teams.

Responsibilities

• Own the core programming language ecosystem and shared abstractions powering Nubank's backend microservices.
• Oversee, govern, and elevate foundational infrastructure libraries used by 4,000+ microservices.
• Ensure internal libraries are stable, idiomatic, and maintained to the highest standards across languages.

Skills

Systems expertise

Abstraction at scale

Polyglot architectures

Stable software design

Leadership across teams

Job description

About Nu

Nu is the leading digital bank in Latin America, serving 135 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.

About Nu

Nu is the leading digital bank in Latin America, serving 135 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 Most Influential Companies, Fast Company’s Most Innovative Companies, and Forbes World’s Best Banks.

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The Opportunity: Building the Bedrock of Nubank's Future

Nubank was built on bold technical choices: emphasizing simplicity, immutability, and state-of-the-art concurrency as the foundation for a global financial revolution. Today, as we scale to serve our customers globally and enter a new era of AI-driven engineering, we are doubling down on our commitment to foundational technical excellence.

As a Library Architect, you will take ownership of the core programming language ecosystem and shared abstractions that power our backend microservices. This role will oversee, govern, and elevate Nubank's foundational infrastructure architecture.

You will help define the "Nubank Way" of building resilient core software libraries and oversee how they interact across the bank's broader programming language landscape. You will ensure that our internal libraries—which support 4,000+ microservices—are stable, idiomatic, and maintained to the highest standards.

Core Qualifications

• Deep Expertise in Systems: Proven deep knowledge, core competency, and active experience building high-throughput, fault-tolerant backend ecosystems at scale.
• Large-Scale Abstraction Specialist: Demonstrated experience abstracting complex domain logic and standardizing libraries across large-scale distributed architectures (hundreds to thousands of microservices).
• Cross-Language Proficiency: Deep understanding of polyglot architectures, runtime environments, and how core abstractions interface across multiple programming languages.
• Stability Obsessed: Uncompromising belief in high-integrity, forward-compatible software design capable of operating reliably for years without breaking changes.
• Executive & Horizontal Influence: Proven ability to navigate complex organizational structures, partner with senior tech leadership, and drive unified engineering standards across teams facing high delivery pressure.
  
  

Why Join Now?

This role reports directly into senior technical leadership. You will have the mandate to fix the foundation of one of the world's most sophisticated technical environments. We are committed to finding the right structural balance for the world’s top specialized talent.

If you are energized by these challenges and want to work with a world-class, senior team defining the next decade of fintech at scale, ensuring our foundational libraries remain the stable, elegant bedrock of Nubank’s global evolution, this is the place for you!

Our Benefits

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