Stealth Startup
Founding Senior Telephony Engineer [32481]
Stealth Startup, Redwood City, California, United States, 94061
Founding Senior Telephony Engineer [32481]
Founding Senior Telephony Engineer [32481]
3 days ago Be among the first 25 applicants Get AI-powered advice on this job and more exclusive features. We're not just automating calls—we’re transforming how the world communicates. Our AI voice agents are reshaping sales, support, and customer engagement for leading brands. Backed by Alt Capital, Y Combinator, and top-tier investors, we've raised $4.7M in seed funding and hit $14M ARR with just 12 people. We’re one of the fastest-growing Voice AI startups and we're on a mission to become the standard for voice automation at scale. About the Role As a Founding Senior Telephony Engineer, you’ll own the foundation of our telephony stack, building the critical systems that connect our AI voice agents to the real world. From low-level SIP features to integrating with global carriers and CCaaS platforms, your work will directly impact call quality, reliability, and customer experience. You’ll move fast, collaborate with customers, and help define the gold standard for AI voice infrastructure. Key Responsibilities Lead design and implementation of core telephony features, including SIP server enhancements and proxy logic. Build and extend our SIP infrastructure to support scalable, low-latency audio routing and call control. Collaborate with customers to support complex SIP integrations with CCaaS platforms and third-party providers. Evaluate and integrate with global telephony carriers to optimize deliverability, latency, and transfer logic. Investigate and debug call failures via PCAP analysis, SIP traces, and carrier logs to improve reliability. Work cross-functionally with platform and infra teams to ensure telephony systems scale with usage growth. Turn feedback from customer calls into robust and maintainable telephony improvements. Have 5+ years as a Telephony Engineer, VoIP Engineer, or equivalent low-latency networking role. Have deep experience with SIP, RTP, and debugging voice quality issues with PCAPs and trace tools. Have built or extended SIP proxies, PBXs, or call routing logic in production systems. Thrive in fast-paced, ambiguous environments and take ownership like a founder. Communicate clearly, collaborate well, and enjoy solving real-world problems with users. Familiarity with Asterisk/FreeSWITCH/Kamailio or relevant SIP proxy / SIP servers. Job Type : Full-time, 70 hr/week (50 hr/week onsite with flexible hours + 20 hr/week work from home) Cash : $215k–$290k Equity : 0.3%–0.6% Location : Redwood City, CA, US US Visas : Sponsors Visa & Green Card Other Benefits Unlimited breakfast, lunch, dinner, and snacks Gym and daily commute fee reimbursement Internet and phone bills covered Compensation Philosophy Best Offer Upfront : Choose from three cash-equity balance options; no negotiation needed. Top 1% Talent : Above-market pay (top 5 percentile) to attract exceptional builders. High Ownership : Small teams, >$1M revenue/employee, and significant equity. Performance-Based : Offers tied to interview performance, not experience or past salaries. Seniority level
Seniority level Mid-Senior level Employment type
Employment type Full-time Job function
Industries Technology, Information and Internet Referrals increase your chances of interviewing at Stealth Startup by 2x Get notified about new Telephony Engineer jobs in
Redwood City, CA . Sunnyvale, CA $111,000.00-$164,000.00 3 days ago San Leandro, CA $75,000.00-$175,000.00 1 month ago Atherton, CA $150,000.00-$200,000.00 5 months ago Fremont, CA $170,000.00-$240,000.00 1 week ago San Francisco, CA $140,000.00-$270,000.00 8 months ago Mountain View, CA $40.00-$60.00 1 month ago Sunnyvale, CA $170,000.00-$240,000.00 2 days ago South San Francisco, CA $100,000.00-$125,000.00 2 days ago Sunnyvale, CA $139,000.00-$200,000.00 5 days ago Hardware Engineer, Platforms, University Graduate
Sunnyvale, CA $105,000.00-$151,000.00 1 week ago Mountain View, CA $88,000.00-$165,500.00 1 year ago Mountain View, CA $130,000.00-$160,000.00 1 month ago Electrical Engineer - Autonomy & Robotics
Newark, CA $110,000.00-$130,000.00 1 week ago Mountain View, CA $150,000.00-$230,000.00 1 month ago Alameda County, CA $130,000.00-$170,000.00 1 week ago Menlo Park, CA $139,000.00-$200,000.00 2 weeks ago San Mateo, CA $187,700.00-$281,500.00 2 weeks ago Sunnyvale, CA $72,100.00-$114,700.00 1 week ago We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI.
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Founding Senior Telephony Engineer [32481]
3 days ago Be among the first 25 applicants Get AI-powered advice on this job and more exclusive features. We're not just automating calls—we’re transforming how the world communicates. Our AI voice agents are reshaping sales, support, and customer engagement for leading brands. Backed by Alt Capital, Y Combinator, and top-tier investors, we've raised $4.7M in seed funding and hit $14M ARR with just 12 people. We’re one of the fastest-growing Voice AI startups and we're on a mission to become the standard for voice automation at scale. About the Role As a Founding Senior Telephony Engineer, you’ll own the foundation of our telephony stack, building the critical systems that connect our AI voice agents to the real world. From low-level SIP features to integrating with global carriers and CCaaS platforms, your work will directly impact call quality, reliability, and customer experience. You’ll move fast, collaborate with customers, and help define the gold standard for AI voice infrastructure. Key Responsibilities Lead design and implementation of core telephony features, including SIP server enhancements and proxy logic. Build and extend our SIP infrastructure to support scalable, low-latency audio routing and call control. Collaborate with customers to support complex SIP integrations with CCaaS platforms and third-party providers. Evaluate and integrate with global telephony carriers to optimize deliverability, latency, and transfer logic. Investigate and debug call failures via PCAP analysis, SIP traces, and carrier logs to improve reliability. Work cross-functionally with platform and infra teams to ensure telephony systems scale with usage growth. Turn feedback from customer calls into robust and maintainable telephony improvements. Have 5+ years as a Telephony Engineer, VoIP Engineer, or equivalent low-latency networking role. Have deep experience with SIP, RTP, and debugging voice quality issues with PCAPs and trace tools. Have built or extended SIP proxies, PBXs, or call routing logic in production systems. Thrive in fast-paced, ambiguous environments and take ownership like a founder. Communicate clearly, collaborate well, and enjoy solving real-world problems with users. Familiarity with Asterisk/FreeSWITCH/Kamailio or relevant SIP proxy / SIP servers. Job Type : Full-time, 70 hr/week (50 hr/week onsite with flexible hours + 20 hr/week work from home) Cash : $215k–$290k Equity : 0.3%–0.6% Location : Redwood City, CA, US US Visas : Sponsors Visa & Green Card Other Benefits Unlimited breakfast, lunch, dinner, and snacks Gym and daily commute fee reimbursement Internet and phone bills covered Compensation Philosophy Best Offer Upfront : Choose from three cash-equity balance options; no negotiation needed. Top 1% Talent : Above-market pay (top 5 percentile) to attract exceptional builders. High Ownership : Small teams, >$1M revenue/employee, and significant equity. Performance-Based : Offers tied to interview performance, not experience or past salaries. Seniority level
Seniority level Mid-Senior level Employment type
Employment type Full-time Job function
Industries Technology, Information and Internet Referrals increase your chances of interviewing at Stealth Startup by 2x Get notified about new Telephony Engineer jobs in
Redwood City, CA . Sunnyvale, CA $111,000.00-$164,000.00 3 days ago San Leandro, CA $75,000.00-$175,000.00 1 month ago Atherton, CA $150,000.00-$200,000.00 5 months ago Fremont, CA $170,000.00-$240,000.00 1 week ago San Francisco, CA $140,000.00-$270,000.00 8 months ago Mountain View, CA $40.00-$60.00 1 month ago Sunnyvale, CA $170,000.00-$240,000.00 2 days ago South San Francisco, CA $100,000.00-$125,000.00 2 days ago Sunnyvale, CA $139,000.00-$200,000.00 5 days ago Hardware Engineer, Platforms, University Graduate
Sunnyvale, CA $105,000.00-$151,000.00 1 week ago Mountain View, CA $88,000.00-$165,500.00 1 year ago Mountain View, CA $130,000.00-$160,000.00 1 month ago Electrical Engineer - Autonomy & Robotics
Newark, CA $110,000.00-$130,000.00 1 week ago Mountain View, CA $150,000.00-$230,000.00 1 month ago Alameda County, CA $130,000.00-$170,000.00 1 week ago Menlo Park, CA $139,000.00-$200,000.00 2 weeks ago San Mateo, CA $187,700.00-$281,500.00 2 weeks ago Sunnyvale, CA $72,100.00-$114,700.00 1 week ago We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI.
#J-18808-Ljbffr