Sr Principal Engineer

At F5, we strive to bring a better digital world to life. Our teams empower organizations across the globe to create, secure, and run applications that enhance how we experience our evolving digital world. We are passionate about cybersecurity, from protecting consumers from fraud to enabling companies to focus on innovation. 
 

Everything we do centers around people. That means we obsess over how to make the lives of our customers, and their customers, better. And it means we prioritize a diverse F5 community where each individual can thrive.

Sr Principal Engineer

Position Summary:

Life at F5 is never dull. We are constantly identifying industry trends and disruptions, then innovating to get ahead of future customer needs—creating application services that help the world's leading organizations deliver their critical business apps faster and with the highest levels of flexibility, security, performance, and quality.

We are looking for senior principal UI engineer to design and implement easy-to-use features for BIG-IP and BIG-IQ Central Manager products. BIG-IP offers the most comprehensive solution for security and traffic management for apps spanning on-premises and multi-cloud architectures. This position provides technical opportunities that can make a significant impact on how our customers use BIG-IP and manage highly secure and performant applications.

Responsibilities:

• Collaborate with Architects to define and implement scalable UI architecture.
• Lead the design of reusable component libraries and design systems.
• Drive development of complex UI features and ensure high performance across devices and browsers.
• Optimize rendering, responsiveness, and accessibility of web applications.
• Set and enforce coding standards, best practices, and guidelines for UI development.
• Conduct deep code reviews and ensure maintainability and scalability.
• Mentor senior and mid-level UI guide teams in adopting modern front-end frameworks and tools.
• Work closely with UX designers, product managers, and backend engineers to deliver cohesive user experiences.
• Translate design mockups and business requirements into high-quality code.
• Evaluate emerging UI technologies and frameworks (e.g., WebAssembly, WASM, micro frontends).
• Lead proof-of-concept initiatives and drive innovation in UI/UX.
• Champion performance optimization (lazy loading, code splitting, etc.).
• Ensure compliance with accessibility standards (WCAG, ARIA).
• Improve developer productivity through tooling (e.g., linters, build tools, CI/CD for front-end).
• Contribute to automated testing strategies (unit, integration, visual regression).

Knowledge, Skills, Abilities:

• Expert-level proficiency in JavaScript/TypeScript, React, Angular.
• Deep understanding of HTML5, CSS3, SASS/LESS, and responsive design.
• Experience with state management.
• Familiarity with Web Performance APIs, Accessibility APIs, and Security best practices.
• Strong grasp of component-based architecture, micro frontends, and design systems.
• Experience integrating front-end with RESTful APIs, and backend services.
• Experience with CI/CD pipelines, test automation (Jest, Cypress, Playwright).
• Excellent communication and collaboration skills.
• Ability to influence technical direction and drive consensus.
• Strong problem-solving and debugging abilities.

Qualifications:

• Bachelor's degree (or above, Graduate degree preferred) in computer science or equivalent professional experience with 12+ years.
• Ability to work flexible hours for better collaboration with international teams.

The Job Description is intended to be a general representation of the responsibilities and requirements of the job. However, the description may not be all-inclusive, and responsibilities and requirements are subject to change.

Please note that F5 only contacts candidates through F5 email address (ending with ) or auto email notification from Workday (ending with or ).

Equal Employment Opportunity

It is the policy of F5 to provide equal employment opportunities to all employees and employment applicants without regard to unlawful considerations of race, religion, color, national origin, sex, sexual orientation, gender identity or expression, age, sensory, physical, or mental disability, marital status, veteran or military status, genetic information, or any other classification protected by applicable local, state, or federal laws. This policy applies to all aspects of employment, including, but not limited to, hiring, job assignment, compensation, promotion, benefits, training, discipline, and termination.  F5 offers a variety of reasonable accommodations for candidates. Requesting an accommodation is completely voluntary. F5 will assess the need for accommodations in the application process separately from those that may be needed to perform the job. Request by contacting