Founding Senior Full-Stack Engineer | Equity & Impact

Sarsfield Group; Redwood City (CA); On-site; USD 180,000 - 260,000; Full time

Benefits offered by this job

Unlimited meals and snacks

Gym and commute reimbursement

Job summary

Our client, a fast-growing YC-backed Voice AI startup, is seeking a Founding Senior Full-Stack Engineer in Redwood City, CA. You’ll build the core platform powering millions of AI-driven conversations using React, TypeScript, and Node.js.

You’ll own features end-to-end, from architecture to production deployment, integrate telephony, dashboards, and analytics, and support onboarding. Equity 0.25–0.45% with unlimited meals, gym, and commute reimbursement; full-time on-site role.

Qualifications

• 2+ years of full-stack experience with React, TypeScript, Node.js, or Python.
• CS/CE degree or equivalent practical experience.
• Ownership mindset with the ability to solve problems independently.
• Thrives in fast-paced, dynamic environments.
• Strong communication and collaboration skills.

Responsibilities

• Develop core features including prompt orchestration, dashboards, analytics, and telephony integrations.
• Build full-stack systems from polished UIs to robust APIs and DevOps workflows.
• Own projects end-to-end from architecture to production deployment.
• Support customer onboarding and translate feedback into product improvements.

Skills

React

TypeScript

Node.js

Python

Education

CS/CE degree or equivalent practical experience

Job description

Our client, a fast-growing YC-backed Voice AI startup, is seeking a Founding Senior Full-Stack Engineer in Redwood City, CA. You’ll build the core platform powering millions of AI-driven conversations using React, TypeScript, and Node.js.

You’ll own features end-to-end, from architecture to production deployment, integrate telephony, dashboards, and analytics, and support onboarding. Equity 0.25–0.45% with unlimited meals, gym, and commute reimbursement; full-time on-site role.