Software Engineer II - Voice Client

Company: Five9
Location: San Ramon
Posted on: February 15, 2026

Job Description:

Job Description Job Description 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. The Voice Client team at Five9 is seeking a passionate and experienced Software Engineer II to help build and enhance the voice solutions that power our industry-leading contact center platform. This person will play a key role in developing high-quality, reliable, and high-performing voice applications across desktop (Mac and Windows) and web platforms using technologies such as SIP, WebRTC, ICE, and Web Sockets. This role requires strong technical expertise, problem-solving ability, and close collaboration with cross-functional teams to deliver exceptional audio quality and customer experiences. You'll also have the opportunity to engage directly with customers, leveraging feedback to continuously improve and evolve our voice solutions for greater business impact. Key Responsibilities : Be part of an agile team to develop a scalable, highly available global voice platform. Understand performance and scalability principles and apply when developing software. Collaborate with Product Managers, Architects, Engineering leaders and test engineers. Mentor and train junior team members. Key Requirements : 5 years of industry experience in software development and troubleshooting VOIP systems. Great understanding on WebRTC in browser and/or SIP signalling. Proficient and expert in JavaScript . Additionally have a minimum of two years of practical experience in the second language between C++ and Java. Experience in troubleshooting tools, audio media analysis and good debugging skills. Experience working on complex problems and systems. Experience working within an Agile/Scrum team. Positive, self-motivated and enthusiastic attitude with a strong-sense of ownership. Strong communication skills, both verbal and written. Bachelor's degree (or equivalent /above) in relevant discipline. Preferrable Skills: Good understanding of VOIP protocols like SIP, RTP, RTCP and other network protocols. Experience in telecom or IoT field. Experience with Contact Centre, IVR, Virtual Agents and telecommunications service providers is advantageous. Work Location: This role is fully remote for candidates who reside outside the 50 mile radius of our San Ramon office. For candidates who reside within 50 miles of our San Ramon location, this role is Hybrid and would require 3 days a week (M, W, TH) in our San Ramon office. As part of our continued commitment to diversity, equity, and inclusion, Five9 supports pay transparency during the entire recruitment process. Actual compensation packages are based on several factors that are unique to each candidate including, but not limited to: skill set, depth of experience, certifications, and specific work location. The range displayed reflects the minimum and maximum target for new hire salaries for the job across the United States. Your recruiter can share more about the specific compensation package during your hiring process. Additionally, the total compensation package for this position may also include an annual performance bonus, stock, and/or other applicable incentive compensation plans. Our total reward package also includes: Health, dental, and vision coverage, beginning on the first day of employment. Five9 covers 100% of the employee portion of the health, dental and vision coverage and shares a high portion of the dependent cost. We also offer Short & Long-Term Disability, Basic Life Insurance, and a 401k saving plan with employer matching. Access to an innovative mental health support platform that offers personalized care and resources in areas such as: therapy, coaching and self-guided mindfulness exercises for all covered employees and their covered dependents. Generous employee stock purchase plan. Paid Time Off, Company paid holidays, paid volunteer hours and 12 weeks paid parental leave. All compensation and benefits are subject to the requirements and restrictions set forth in the applicable plan documents and any written agreements between the parties. The US base salary range for this role is below. $72,500—$168,300 USD 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. 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.

Keywords: Five9, San Rafael , Software Engineer II - Voice Client, Engineering , San Ramon, California