Senior Software Engineer, UI Performance

About the role

This role owns the design, implementation, and continuous optimization of the embedded UI framework that powers the core Roku viewing experience. You will be responsible for extending the high-performance grid rendering component that drives app layout and navigation across millions of devices globally. In this position, you will investigate and resolve complex performance bottlenecks in UI rendering, memory usage, and input latency under real-world streaming conditions. You will build and maintain internal tools that empower other engineers to measure, analyze, and improve UI behavior at scale. Collaboration with UI design, product management, and cross-functional engineering teams will ensure that new features align with platform strategy and user expectations. You will leverage agentic coding practices to prototype, test, and iterate on solutions rapidly while maintaining strict reliability standards. Ultimately, your work will directly influence the responsiveness and delight of the streaming experience for every Roku user.

What you'll do

• Investigate and profile UI rendering pipelines to identify sources of jank, dropped frames, and input lag in grid-based navigation components.
• Architect and evolve the embedded UI framework to support new screen shapes, resolutions, and interactive behaviors across diverse TV hardware.
• Develop performance testing tools and automated benchmarks that validate UI responsiveness and memory footprint during development.
• Collaborate closely with the Home Screen and EPG teams to integrate feature requests while preserving system-wide performance and stability.
• Design and implement reusable UI components that balance flexibility, scalability, and runtime efficiency.
• Instrument the UI stack with fine-grained telemetry to surface performance regressions early in the development cycle.
• Partner with system architects to translate high-level product goals into concrete, performant UI layer implementations.
• Lead code reviews and technical discussions to elevate the quality and maintainability of UI infrastructure across teams.
• Experiment with agentic coding workflows to accelerate feature development, validate outputs, and integrate feedback into the build process.
• Mentor engineers on best practices for writing efficient, debuggable UI code that works consistently across the Roku ecosystem.
• Define and track key performance indicators to ensure that shipped improvements move the needle on real-user experience.
• Champion accessibility and internationalization considerations in UI component design and verification.
• Support on-call responsibilities to triage and resolve critical UI performance issues in production environments.
• Continuously explore emerging UI patterns and hardware capabilities to future-proof the streaming interface.

Requirements

• Must have a strong background in building high-performance user interfaces for consumer electronics or similar large-scale applications.
• Must be proficient in modern frontend technologies relevant to TV-based UI frameworks and rendering optimization.
• Must demonstrate experience with debugging performance issues in complex, real-time user interfaces.
• Must be comfortable working in a fast-paced, collaborative environment where priorities evolve with the product roadmap.
• Must communicate effectively with both technical and non-technical stakeholders to align on goals and trade-offs.
• Must have a history of owning end-to-end feature delivery from design through implementation and post-launch evaluation.
• Must be fluent in at least one systems-level programming language commonly used for UI infrastructure.
• Must be willing to work closely with cross-functional teams to ensure that UI changes integrate cleanly with platform services.

About the team

Teamwork makes the stream work. Roku is changing how the world watches TV. Roku is the #1 TV streaming platform in the U.S., Canada, and Mexico, and we've set our sights on powering every television in the world. Roku pioneered streaming to the TV. Our mission is to be the TV streaming platform that connects the entire TV ecosystem. We connect consumers to the content they love, enable content publishers to build and monetize large audiences, and provide advertisers unique capabilities to engage consumers. From your first day at Roku, you'll make a valuable - and valued - contribution. We're a fast-growing public company where no one is a bystander. We offer you the opportunity to delight millions of TV streamers around the world while gaining meaningful experience across a variety of disciplines.

What the team works on

This team spends most of its time building and improving the UI framework and components that power Roku user experiences. Our roadmap helps us accelerate our growth and scale, putting surprising new features into the hands of tens of millions of Roku users worldwide. Our developers and engineers are owners. They are motivated from within, finding and taking on a feature or project simply because that problem needs to be solved and shipped. But that individual must work together with different engineering teams, UI design, product teams, and business leadership to make things happen, which means that engineers succeed here because they can maintain that independent spirit and motivation within a deeply collaborative environment. We are the pragmatic dreamers inventing and re-inventing the world of streaming media.

Requirements (expanded)

• Demonstrated experience contributing to large-scale, performance-critical UI systems, ideally within consumer electronics or set-top box environments.
• Proven ability to diagnose and resolve rendering, layout, and input latency issues in complex UI frameworks.
• Strong grasp of component-based UI architectures, lifecycle management, and state handling within streaming platforms.
• Experience defining, implementing, and iterating on telemetry strategies that expose actionable performance insights.
• Comfort working with cross-functional stakeholders to balance feature velocity against system performance and reliability.
• Willingness to engage with open-source practices and contribute back to shared infrastructure where applicable.
• Familiarity with content delivery constraints, TV hardware diversity, and regional compliance considerations relevant to streaming platforms.

Nice to have

• Experience contributing to open-source UI frameworks or performance-critical client-side systems.
• Familiarity with agentic coding tools and workflows such as Claude Code or Cursor.
• Knowledge of TV streaming architectures, home screen implementations, and electronic program guide systems.

Practical notes

The role is based in Cambridge, United Kingdom. Engagement type and hours are defined in the source documentation.