Staff 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 are seeking a Staff Voice Engineer with proven expertise in SIP routing, SIP trunks, calling plans, and VoIP architectures to lead the technical direction of our global voice platform while remaining hands-on in design, coding, and implementation.

In this senior leadership role, you will define architecture standards, drive automation strategies, and deliver scalable, event-driven solutions for provisioning, monitoring, and optimizing our voice services.

You will be expected to design, code, test, and deploy microservices and APIs for SIP trunk provisioning, routing, and analytics, collaborating directly with engineering teams while influencing product and platform strategy.

• 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.

Key Responsibilities
Voice Platform Architecture & Strategy

• Define and own the end-to-end architecture for SIP trunking, routing, and calling plan services.
• Establish routing strategies for Least Cost Routing (LCR), redundancy, and carrier optimization.
• Lead capacity planning and carrier interconnect design to support global scale.
• Drive adoption of best practices for SIP routing resiliency, failover, and codec optimization.

Hands-On Engineering, Automation & Microservices

• Actively contribute to the design, coding, and deployment of Spring Boot microservices for voice provisioning, routing management, and real-time monitoring.
• Develop and maintain REST API endpoints and workflows for SIP trunk onboarding, routing updates, and calling plan automation.
• Implement event-driven architecture (Kafka, RabbitMQ, etc.) to publish real-time call quality and operational events for analytics.
• Build automation scripts, pipelines, and integrations to reduce manual intervention in voice operations.

Voice Observability & Analytics

• Define key voice performance indicators (MOS, jitter, packet loss, call setup times) and ensure accurate telemetry collection.
• Develop analytics dashboards and data pipelines for internal operational teams and customers.
• Set standards for alerting, SLA reporting, and proactive incident detection.

Technical Leadership & Mentorship

• Serve as the technical authority for SIP routing, voice automation, and microservices design.
• Mentor engineers in voice architecture, coding best practices, and automation frameworks.
• Influence product and engineering roadmaps to ensure alignment with long-term platform goals.

Testing & Quality Standards

• Set testing and validation strategies for all voice-related services, including failover, routing logic, and interoperability.
• Code and maintain test automation using tools such as SIPp, custom scripts, and CI/CD integration.
• Drive continuous improvement in QA, monitoring, and deployment processes.

Required Skills & Experience

• 10+ years in telecommunications engineering, with extensive experience in SIP routing, SIP trunks, and global calling plans.
• Proven track record as a technical leader or architect in large-scale voice service deployments.
• Expert-level knowledge of SIP call flows, routing algorithms, and carrier interoperability.
• Strong hands-on experience with Spring Boot microservices, Java coding, and event-driven architectures.
• Proficiency in REST API design for telecom provisioning and automation.
• Deep understanding of telecom protocols (SIP, RTP, WebRTC) and media negotiation.
• Experience in voice analytics, metrics pipelines, and dashboard integration.
• Familiarity with testing and automation tools (SIPp, scripting in Python/Bash/Java).
• Strong coding, debugging, and performance optimization skills for real-time voice systems.
• Exceptional communication and stakeholder management skills, with the ability to influence technical direction at the organizational level.

Preferred Skills

• Experience with cloud-based voice platforms (e.g., Webex Calling, Broadsoft, Twilio, Zoom Phone, AWS Chime, Teams Direct Routing).
• Knowledge of CI/CD pipelines for telecom applications.
• Familiarity with cloud infrastructure (AWS, GCP, Azure) for hosting and scaling voice services.
• Understanding of security best practices in SIP and VoIP, including encryption, fraud prevention, and compliance requirements.
• Experience integrating voice automation workflows with OSS/BSS systems and customer portals.

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:

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

---