Sr Software Engineer - UI

Join us in bringing joy to customer experience. Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide.

Living our values everyday results in our team-first culture and enables us to innovate, grow, and thrive while enjoying the journey together. We celebrate diversity and foster an inclusive environment, empowering our employees to be their authentic selves.

Role Overview

We're looking for a talented Frontend Engineer who leads with UI but isn't afraid to go deep. You thrive in a fast moving environment, ship polished interfaces with TypeScript and React and embrace AI-assisted development as a core part of your workflow. This role is front-end-first, but the expectation is that you'll grow into full stack ownership over time.

How You Contribute

Design and build responsive, performant UIs using React, TanStack, Zustand, TypeScript and/or JavaScript

Collaborate on feature development end-to-end, gradually taking on backend work as you grow

Use GitLab for version control, CI/CD pipelines, merge request workflows, and issue tracking

Deploy and manage workloads on Google Cloud Platform CDN , working alongside with services like GKE, and Cloud Storage

Leverage AI-assisted (vibe coding) tools to accelerate development — you're comfortable using Copilot, Cursor, Claude, or similar tools as a force multiplier

Write clean, maintainable code with strong typing and component reuse in mind

Partner closely with designers and product to translate specs into real, shippable experiences

Participate in code reviews, retrospectives, and architectural discussions

Required Skills and Qualifications

5+ years of + post-internship experience with React and TypeScript.

Solid JavaScript/ TypeScript, HTML, CSS

Knowledge of UI Component Libraries, Web Accessibility, Internationalization

Ability to work with test libraries (Jest, Playwright)

Proficient in React, TanStack, Zustand

Engineering focus

Overall system knowledge

Working knowledge of Jira, GitLab, Visual Studio, CI/CD

Proficient in Google Cloud Platform, Kubernetes, BigQuery, Cloud SQL, CDN

Ability to use Claude Code

Desirable Qualifications

AI Tools

Micro Front End Architecture

Java/ Springboot

Database SQL/ NoSQL

Five9 embraces diversity and is committed to building a team that represents a variety of backgrounds, perspectives, and skills. The more inclusive we are, the better we are. Five9 is an equal opportunity employer.

This role is hybrid and requires 3 days a week in office .

Five9 embraces diversity and is committed to building a team that represents a variety of backgrounds, perspectives, and skills. The more inclusive we are, the better we are. Five9 is an equal opportunity employer.

Five9 is committed to providing reasonable accommodations for qualified individuals with disabilities throughout the application and interview process. If you need assistance or an accommodation due to a disability, please contact us at [email protected] to request an accommodation. Requests will be handled confidentially and in accordance with applicable law.

View our privacy policy, including our privacy notice to California residents here: https://www.five9.com/pt-pt/legal .

Note: Five9 will never request that an applicant send money as a prerequisite for commencing employment with Five9.