Senior Full Stack Software Engineer

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.

We’re seeking talented Full Stack Developer to become part of our diverse, forward- thinking team. You’ll work in a dynamic, global environment where innovation, collaboration, and cutting-edge technology drive real business impact. In this role, you’ll help deliver Five9 global voice features. From initial concept through to delivery, you’ll be involved in every step of the software development lifecycle - translating requirements into technical designs, writing clean and efficient code, and integrating with complex systems.

You’ll join our team that thrives on continuous learning, embraces new technologies, and values smart engineering. Whether deploying cloud-native solutions orintegrating secure, scalable APIs, your work will directly shape how organizations operatein the digital age.

If you’re passionate about full-stack development, excited by the opportunity to work onmpactful solutions, and eager to collaborate with like-minded engineers around the world,we’d love to meet you.* This position is based out of one of the offices of our affiliate Acqueon Technologies in India, and will adopt the hybrid work arrangements of that location. You will be a member of the Acqueon team with responsibilities supporting Five9 products, collaborating with global teammates based primarily in the United States.

• Designing and developing both frontend and backend components using modern
  frameworks

• Collaborating with cross-functional teams to deliver robust, maintainable solutions

• Building responsive, user-focused interfaces based on wireframes (e.g., Figma)

• Writing clean, scalable code and implementing state management using tools like
  Redux

• Integrating systems and services using RESTful APIs and secure authentication
  methods (e.g., JWT)

• Participating in agile development processes, including sprint planning and code
  reviews

• Testing, debugging, and optimizing applications across environments

• Degree in Computer Science, Technical Science, or similar

• Experience in software development projects across front-end and back-end

• 5 yrs Hands-on experience in:
  ◦ Java, JavaScript, Python, TypeScript
  ◦ React, Redux (State Management), JSX
  ◦ Spring Boot, Spring MVC, Angular, Vue.js

• Proficient in using:
  ◦ Git (GitLab), Jira, Confluence, SVN, Jenkins
  ◦ CSS, Wireframing tools (e.g., Figma)

• Understanding of data structures and clean code principles

• Experience in building and consuming RESTful APIs

• Familiarity with modern authentication mechanisms such as JWT

• Experience with unit, integration, system, and regression testing

• Experience with cloud platforms: Azure, AWS, or GCP

• Strong interest in continuous learning and growing technical skills

• Excellent collaboration, problem-solving, and communication skills

• Fluent in English, both written and spoken

Five9 embraces diversity and is committed to building a team that represents a variety of backgrounds, perspectives, and skills. The more inclusive we are, thebetter we are. Five9 is an equal opportunity employer. Our headquarters are located in the beautiful Bishop Ranch Business Park in San Ramon, CA.