Skip to content
PhonelyPhonelySan Francisco, CA

Full Stack Engineer

Builds and maintains full-stack web applications with React/Next.js, integrates backend APIs and voice AI systems, optimizes performance, and owns UI/UX. Requires 5+ years experience, strong full-stack skills, and TypeScript proficiency in a fast-paced onsite environment.

Salary not listed
On-site5+ YOEFullstack Engineering

About the role

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

Software Stack

Frontend: React, Next.js, TypeScript Backend: Python, microservices, async systems Cloud & Infra: AWS, GCP, Kubernetes, Redis Databases: Firebase, Supabase Observability: Datadog, logging, metrics, tracing Voice AI: SIP, real-time call handling, LLM orchestration Other: CI/CD, testing, resilient architecture

Skills

ReactNext.jsTypeScriptPythonKubernetesAWSGCPRedisFirebaseSupabaseDatadogCI/CD
TheGuarantors

Software Engineer

TheGuarantorsNew York, NY +7

Senior Software Engineer building scalable backend services and modernizing a monolithic platform to microservices for a fintech company's deal flow and underwriting systems. Requires 5+ years experience with Node.js/NestJS, TypeScript, Go, APIs, and distributed systems.

170k – 195k/yr
Remote5+ YOEFullstack Engineering
Mercor

Product Engineer, Talent Experience

MercorSan Francisco, CA

Build and ship polished full-stack features with frontend emphasis across multiple product surfaces for Mercor's AI talent platform. Requires 2-5+ years experience, strong React/TypeScript skills, full-stack capability, and comfort with AI coding tools in a fast-paced onsite environment.

130k – 500k/yr
On-site5+ YOEFullstack Engineering
Mercor

Fullstack Engineer, Assesment

MercorSan Francisco, CA

Build and own backend-heavy full-stack systems for Mercor's assessment platform, designing evaluation pipelines that combine human judgment with AI-powered scoring for vetting top AI talent. Requires 3+ years professional software engineering experience with strong backend fundamentals and comfort across the stack.

130k – 500k/yr
On-site3+ YOEFullstack Engineering
ZoomInfo

Software Engineer III

ZoomInfoBethesda, MD

Full-stack Software Engineer building customer-facing features and AI-powered tools for sales conversation analytics. Requires 3-6 years experience with either backend (Python/Node.js) or frontend (React/Angular) proficiency plus eagerness to work across the stack, databases, and search tech.

112k – 176k/yr
Hybrid3+ YOEFullstack Engineering
Rula

Software Engineer 2

RulaLos Angeles, CA

Software Engineer 2 on the Patient Onboarding team at Rula, building and evolving systems for patient acquisition, registration, eligibility verification, and onboarding flows. Requires 3+ years experience with strong full-stack or backend skills, end-to-end feature ownership, and active use of AI coding tools.

145k – 171k/yr
Remote3+ YOEFullstack Engineering