Senior Founding Full Stack Engineer

Mission.dev; San Francisco (CA); On-site; USD 200,000 - 280,000; Full time

Benefits offered by this job

Relocation package

Visa sponsorship

Medical, dental, vision insurance

Meal allowance

Gym reimbursement

Commute reimbursement

Phone & internet reimbursement

Equity 0.25–0.45%

Job summary

Mission.dev is seeking a Senior Founding Full Stack Engineer in San Francisco to design and build the core AI voice agent platform. You will own frontend performance and backend orchestration, from prompt engineering to telephony integrations, delivering features for enterprise customers.

You’ll collaborate directly with founders, drive the full development lifecycle, and contribute to production deployments in a high-ownership, fast-paced environment.

Qualifications

• 3–8 years of professional full-stack experience.
• Proven mastery of React and TypeScript for high-performance frontend.
• Backend development experience; language are flexible.
• Bachelor’s degree in Computer Science or Computer Engineering with GPA ≥3.8.
• End-to-end ownership of features: design, API, deployment.

Responsibilities

• Architect and build core features for AI voice agents and dashboards.
• Develop analytics platforms and telephony integrations for enterprise scale.
• Own features from design through production deployment.
• Collaborate with founders to translate requirements into tech solutions.
• Onboard enterprise customers and ensure successful AI solution deployment.
• Optimize frontend performance and state management for real-time visuals.
• Maintain high code quality and reliability in a fast-paced CD environment.

Skills

React

TypeScript

Education

Bachelor’s degree in CS/CE

Tools

WebRTC

Twilio

SIP

Job description

AI Developer, Back-End Developer, Front-End Developer

Required skills: TypeScript, React

Nice to have skills: Twilio, WebRTC

Region: United States of America

On-Site Location: San Francisco, CA, USA

A venture-backed, profitable AI company based in the San Francisco Bay Area specializes in developing voice-based AI agents for large-scale enterprise customer service. With a team of fewer than 50 people, the organization operates at a high intensity to ship production-ready solutions for major U.S. corporations. The culture emphasizes direct collaboration with founders and end-to-end problem ownership in a fast-paced environment that prioritizes rapid deployment and technical excellence over traditional corporate structure.

About the Role

As a Senior Founding Full Stack Engineer, you will design and build the core infrastructure behind production-scale AI voice agents. This role requires an equal focus on frontend performance and backend orchestration, covering everything from prompt engineering to telephony integrations. You will own the entire development lifecycle—from initial architecture to production deployment—for features that directly impact enterprise clients. This is a high-impact position intended for engineers who thrive in an intense, high-ownership environment and want to influence the technical direction of a rapidly scaling product.

What You'll Do

• Architect and develop core product features for AI voice agents, including prompt orchestration and real-time dashboards.
• Lead the development of analytics platforms and telephony integrations to support enterprise-scale customer conversations.
• Drive features through the entire software development lifecycle, from initial system design to production deployment.
• Collaborate directly with founders to translate product requirements into high-performance technical solutions.
• Support the technical onboarding of enterprise customers to ensure successful implementation of AI solutions.
• Optimize frontend performance and state management to handle complex, real-time data visualizations.
• Maintain high code quality and system reliability in a fast-moving, continuous delivery environment.

What You Bring

• 3 to 8 years of professional experience in full-stack software engineering.
• Proven mastery of React and TypeScript for high-performance frontend development.
• Strong proficiency in backend development (language is flexible).
• Bachelor’s degree in Computer Science or Computer Engineering from a top-tier academic program with a minimum GPA of 3.8.
• Demonstrated experience owning features end-to-end, including design, API development, and deployment.
• Ability to work onsite five days a week in San Francisco, CA.

Nice to Haves

• Experience with real-time or telephony systems such as WebRTC, SIP, or Twilio.
• Previous experience working with Large Language Models (LLMs) or AI agent products.
• Background as an early engineer at a fast-growing, early-stage startup.
• Base salary of $200,000 – $280,000.
• 0.25% – 0.45% equity stake.
• 100% coverage for medical, dental, and vision insurance.
• $10,000 relocation package and visa sponsorship (H-1B, TN, L-1, E-3, O-1).
• Daily meal allowance plus gym, commute, phone, and internet reimbursement.