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Full Stack Engineer

Phonely· Engineering
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San Francisco, California$160k - $210k + equityFull-timePosted 6mo ago

About the role

Senior Full Stack Engineer (React / Next.js) at Phonely, an AI call centers startup. In-office role in San Francisco, US visa required. High-impact, fast-paced engineering position building frontend and full-stack features with voice AI workflows.

Responsibilities

  • Build and maintain high-performance, responsive web applications using React and Next.js
  • Design and implement end-to-end features across frontend and backend systems
  • Work closely with backend engineers to integrate APIs, real-time systems, and voice AI workflows
  • Own UI/UX quality—craft fast, intuitive, and reliable user experiences
  • Manage state effectively across complex applications (server + client state)
  • Optimize frontend performance (latency, rendering, caching, edge delivery)
  • Build internal tools and dashboards for monitoring, debugging, and controlling AI agents
  • Write clean, maintainable, and well-tested code across the stack
  • Debug production issues and continuously improve reliability and usability
  • Contribute to system design, architecture decisions, and product direction

Qualifications

  • 5+ years of experience building production applications
  • Strong experience with React and Next.js
  • Experience building full-stack applications (API design, backend integration)
  • Solid understanding of TypeScript, modern frontend tooling, and state management
  • Experience working with APIs, real-time systems, and async data flows
  • Understanding of performance optimization and scalable frontend architecture
  • Familiarity with cloud environments, CI/CD, and modern deployment workflows
  • Strong product sense and attention to detail
  • Clear communicator who can work across teams

Skills

Required:ReactNext.jsTypeScriptAPI design
Nice to have:Real-time systems

Benefits

  • Company-paid meals
  • Team activities including running, hiking, and surfing
  • Travel opportunities (Airbnbs in various locations)
Last updated Oct 7, 2026. Interested? Apply on the company site.
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About Phonely

AI call centers

Phonely uses existing call recordings to create a 'AI vocal twin' that can answer customer support calls and match or outperform call center agents. On top of that we've built a Zapier like workflow that lets businesses connect to software or transfer calls just like a person would. Our platform sits on proprietary deterministic LLM that is both cheaper and more accurate than gpt-4o for call center inquiries.

Company profileWebsite

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