Delivering changes to mobile applications is always painful: dealing with store reviews, users that don't update their apps and multiple concurrent versions being used at the same time. Server-Driven UI is an architectural shift that helps teams deal with these problems and allow them to move faster by reducing time to delivery of new features or bug fixes.
At Nubank, we've designed a backend-driven UI framework that has revolutionized how our 3000+ engineers develop our mobile application, enabling them to modify user interfaces, change business logics and create new product flows without app releases. Currently, our framework powers almost every new flow and more than half of our application, serving over 1000 different screens in our product flows to over 100 million customers across multiple countries.
In this talk, we'll explore the advantages and challenges of Server-Driven UIs and bring some insights on the whole journey that led to our current framework:
- Impact Metrics: How Server-Driven UI has increased our deployment frequency to several times per day, reduced feature rollout times from weeks to minutes, and minimized the time to address bugs.
- Engineering Efficiency: How our framework simplified the engineering effort to develop UIs significantly, with a 40% decrease in the resources needed for new feature deployments.
- Creating a Server Driven app: We'll take a look under the hood on how our framework works and examples of UIs running on our app.
- Pitfalls: What are patterns to avoid, what doesn't work and which mistakes have we made across the multiple iterations that got us to our current state
- Future Challenges: As we scale, we face new challenges. We'll discuss these and our strategies for addressing them, ensuring our framework can keep meeting our needs.
Interview:
What is the focus of your work?
I'm currently working on the Mobile Platform team, focused on improving the overall infrastructure of Nubank's mobile app by implementing tooling, frameworks and components that other teams at the company will consume and build their own experiences.
What’s the motivation for your talk?
Over the past years, I was involved in bringing more and more Server Driven UI into Nubank's mobile development workflow, ultimately designing a custom framework to build and control UIs dynamically from the server side. These efforts paid off at the company, allowing us to have a much shorter lead time and improving the experiences we deliver to our customers. I have lots of lessons, pitfalls and tips that I'm eager to share and hopefully bring more developers into thinking about how to incorporate server driven elements into their apps.
Who is your talk for?
My talk is for developers that work with mobile applications and want to expand their toolset to build their experiences. From small concepts that can be incorporated for those entering mobile development to insights on how we've built a complete framework for more advanced ones.
What do you want someone to walk away with from your presentation?
I'd like people that attend my presentation to be able to learn these new concepts, crossing the boundaries of client side implementations and incorporate server driven elements when building the next features of their mobile applications.
What do you think is the next big disruption in software?
For the next couple of years I think the next big disruption will be low/no code development with the growth of AI. Being able to implement software by using visual tools or textual descriptions will lower the entry barrier for more people to get into software development.
Speaker

Rafael Ring
Senior Staff Software Engineer, Mobile Platform Team @Nubank, 10+ Years Working Full Stack
Rafael is a Senior Staff Software Engineer on the Mobile Platform team at Nubank, responsible for the whole infrastructure that powers Nubank's mobile applications. Working full stack for more than a decade, he enjoys dealing with complex projects that span across the whole tech stack and is always searching for ways to innovate how we build tech.