Software Engineer II, Voice Client

Join Five9 as a Software Engineer II, Voice Client

Five9 is a leading provider of cloud contact center software, committed to bringing the power of cloud innovation to customers worldwide. Our team-first culture, driven by our values, fosters innovation, growth, and a thriving environment. We celebrate diversity and empower 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. In this role, you will be crucial in developing high-quality, reliable, and high-performing voice applications across desktop (Mac and Windows) and web platforms. You'll work with technologies such as SIP, WebRTC, ICE, and Web Sockets, requiring strong technical expertise, problem-solving abilities, and close collaboration with cross-functional teams to deliver exceptional audio quality and customer experiences. You'll also engage directly with customers, using 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 them 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 of WebRTC in browser and/or SIP signaling.
• Proficient and expert in JavaScript.
• Minimum of two years of practical experience in either C++ or Java.
• Experience in troubleshooting tools, audio media analysis, and strong 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 a relevant discipline.

Preferable Skills

• Good understanding of VOIP protocols like SIP, RTP, RTCP, and other network protocols.
• Experience in the telecom or IoT field.
• Experience with Contact Center, IVR, Virtual Agents, and telecommunications service providers is advantageous.

Work Location & Compensation

This role is fully remote for candidates residing outside a 50-mile radius of our San Ramon office. For those within 50 miles of San Ramon, it is a Hybrid role requiring 3 days a week (M, W, TH) in the San Ramon office. Five9 supports pay transparency, and actual compensation packages are based on factors like skill set, experience, certifications, and specific work location. The US base salary range for this role is $72,500—$168,300 USD. The total compensation package may also include an annual performance bonus, stock, and/or other incentive plans.

Our total reward package also includes health, dental, and vision coverage (100% employee covered, high portion of dependent cost shared), Short & Long-Term Disability, Basic Life Insurance, a 401k savings plan with employer matching, access to an innovative mental health support platform, generous employee stock purchase plan, Paid Time Off, Company paid holidays, paid volunteer hours, and 12 weeks paid parental leave.

Five9 embraces diversity and is an equal opportunity employer.

Key skills/competency

• VoIP Systems
• WebRTC
• SIP Signaling
• JavaScript Development
• C++ Programming
• Java Development
• Debugging & Troubleshooting
• Scalable Platform Design
• Agile Methodology
• Customer Experience Improvement