Senior Software Engineer, Backend [32751]

Stealth Startup; San Carlos (CA); Hybrid; USD 215,000 - 290,000; Full time

Benefits offered by this job

Unlimited meals

Gym reimbursement

Internet and phone coverage

Job summary

Stealth Startup in Redwood City, CA is hiring a Founding Senior Backend Engineer to shape core systems powering millions of AI-driven conversations. You’ll tackle real-time audio, telephony integrations, and observability tooling while partnering with the founding team.

You’ll own architecture, design scalable backend and DevOps workflows, and lead projects end-to-end. This high-impact role offers rapid feedback, direct customer collaboration, and meaningful ownership in a category-defining

Qualifications

• 2+ years of backend development experience with a CS/CE/EE degree.
• Design scalable backend systems and DevOps workflows for reliable performance across millions of calls.
• Lead complex projects from architecture to production and delivery.
• Collaborate with product and design teams to create intuitive APIs and customer onboarding interfaces.
• Support customer onboarding, troubleshoot issues, and turn feedback into product improvements.

Responsibilities

• Build foundational architecture for the platform, including prompt orchestration, testing frameworks, observability dashboards, and telephony integrations.
• Design scalable backend systems and DevOps workflows for reliability at scale.
• Lead projects from architecture through production and monitoring.
• Collaborate with product/design to deliver intuitive APIs for quick onboarding.
• Onboard customers, resolve issues, and translate feedback into product improvements.

Skills

Backend development

DevOps

APIs

Cloud infrastructure

Education

CS, CE, or EE degree

Tools

Git

CI/CD

Terraform

Job description

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 Backend Engineer, you’ll shape the core systems powering millions of AI-driven conversations. You’ll tackle real-time audio, global telephony, and developer tooling, working across the stack with the founding team. This high-impact role offers rapid feedback loops, customer collaboration, and the chance to define a category-leading product.

Key Responsibilities

• Build foundational architecture for the company's platform, such as prompt orchestration, testing frameworks, observability dashboards, and telephony integrations.
• Design scalable backend systems and DevOps workflows for reliable performance across millions of calls.
• Lead complex projects from architecture to production, driving delivery and monitoring.
• Collaborate with product and design teams to create intuitive APIs and interfaces for quick customer onboarding.
• Support customer onboarding, troubleshoot issues, and turn feedback into product improvements.
• Have 2+ years of backend development experience with a degree in CS, CE, or EE.
• Take ownership like a founder, with a passion for impactful software.
• Thrive in fast-paced, ambiguous environments, solving new problems with curiosity.
• Communicate clearly, collaborate across teams, and drive momentum.
• Have startup experience or grit to adapt, with bonus points for cloud infra/DevOps knowledge.
• Job Type: Full-time, 70 hr/week (50 hr/week onsite with flexible hours + 20 hr/week work from home)
• Cash: 215k - 290k
• Equity: 0.4 - 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 high performers.
• High Ownership: Small teams, >$1M revenue/employee, and significant equity.
• Performance-Based: Offers tied to interview performance, not experience or past salaries.